Back when I was doing digital modes, I wanted a dedicated radio, I used an IC-735 for PSK and it was just fine - I cranked the power down to 30 watts or so, plenty for PSK.  You can probably get one of those for $300.

You are going to build a panel with jacks, each jack connected to the key jack of a single radio?  Should work FB.  As a precaution, you might just use two pair shielded wire but I doubt that's even necessary.  You could use a set of DPST switches but there's a danger of multi-keying with that.  Of course if you use a three circut jack you can use keyer etc.

That would look nice and clean, IMHO.

Given your needs, I think you need to consider whatever passes for business band radio in Mexico - I think I would find the motorola dealer closest to you and have a talk with them.  If there is some commercial value to this event, then perhaps they could give you loaners or something.

Does not sound like you qualify for amateur radio operations.

Couple of thoughts:

Cleaning the grunge off an old beam feels good, makes it go together easier and it's more fun to put back together if it's not covered with mung.

I use the industrial sized green scotchbrite pad and maybe a dash of simple green in a bucket of water.

When reassembling, I use no-alox or whatever DXE sells in a squeeze bottle, made for electrical continuity and easy disassembly in future.

I've painted many an antenna with the Krylon or similar camoflage spray paints - they seems to stick well if the surface is cleaned - for aluminum, I use the above scrubby, rinse really well, then wipe down just before painting with denatured alcohol - mineral spirits would likely do as well.

Take your time - doing a beam you really have to assemble it, tune it, mark and mask it, then paint and reassemble - probably not worth doing on a beam you can't turn over with one person handling it.

Krell?  Nope.  MarkLevinson before he sold out, it's an old piece.  I have the matching preamp and a full set of the CERN spec connectors.  I have B+W speakers of suitable power handling, can't remember the model no.

I was going to suggest that you can use one relay to power additonal relay banks, each of which can be it's own AC supply, but the control signal can come from the master relay.  That way you could also use contactors for the 240 volts for your amplifier.

Wire shelving is a double edged sword, the wires do not support stuff very well, although it ventilates exceptionally well.

I have a Fletcher Ham Desk - which must be one of less than a hundred of them as I think he priced himself out of business, giving 'em away too cheap - that's nice as the top shelf rolls towards you on casters so you can reach behind the hardware, and there's a bottom shelf for power supplies, batteries, dummy load, etc.

I tried to more or less emulate that in this shack, using a dining table that is 36" deep, which is room for deep hardware, wiring behind it and plenty of writing surface in front of the rigs - which I prefer.

The challenege is a wall mounted overshelf - in order to make it 18" deep for my oversized tuners, I needed to source some pretty big special wall brackets and used BIG honking screws - fortunately the wall is solid logs. - and the shelf itself is two boards to make a wide enough surface.  ALWAYS mount wall shelves with an inch space to the wall and if you can, notch out a larger gap between each set of brackets - that way if you need to pass a big plug, you can, then slide it over into the inch gap.  This really helps you run wires.

If I had the room I would either make a walk-behind desk, or put it on wheels so it could be rolled away from the wall - heck you could even put big hinges on one side and swing it aside.  That's ideal for a guy whose always rebuilding his station or messing around with the configuration of the hardware.  A rack-mounted station is sort of a fantasy of mine - or one of those video editing rack desks - those are really pretty neat if you like the commercial look.

So much depends on just how much hardware/plunder you feel your station requires.

Hm.  Well, I have an FT-897, and while it's a fine portable radio and a useful 'shack in a box', I suggest you will outgrow it quickly - which is NOT to say that if you can lay your hands on a used one, that it would not be a good buy - esp. if it came with filters added.  I found the performance greatly enhanced by the SSB narrow filters.

However, I don't operate portable nearly as much as I though I would so mine sits mostly unused these days.

You are right about the battery issue - it's much more cost effective to simply buy a seperate AGM/Gell battery for portable use if and when.

I would recommend that you consider something like a dual band FM VHF/UHF radio and a separate HF/6 meter radio.  And buy a base station radio first then if you find yourself really yearning to operate portable, examine your options at that point - a KX3 will make much more sense then.

Taking the radio out of your station to go operate, then have to reinstall it gets old really, really fast.

What's the old line about the pain of a higher price is forgotten quicker than the pain of buying the wrong or a lousy one and buying twice?

When I finally broke down, I just bough Heil - he's got a couple different price levels if money is that tight.

You can build a hand pushbutton switch for a few bucks or use VOX if you don't want to spend $ on his stuff - although I really like his hand switch, I do believe that's the same 'pickle' that the FAA uses at their ARTCC facilities. 

I have a headset mounted mic.

Booms appeal to me in a Johnny Fever sort of way, and you can use a cordless headset with one.  Now that's freedom, you can still hear the radio whilst refreshing your coffee upstairs...I have a pair of nice cordless RF headphones but not at this QTH.

I buy those little paper tags with strings - easy to write on and you can loop 'em for temporary or tie 'em so they won't come off - if you need it durable, packing tape is applied and it's more weather resistant.

Then I try and put them away where I will remember where the are - and never can find them.  What I should do, and have tried with other spare hardware, is the plastic tote-bins with hinged lids - good for small to medium sized hardware and they are rodent-proof, good for storage in my shed.

The good news is that many of the cords today are totally interchangable - the USB cords for example.

When you look at an Embassy or a major HF communication station, you will notice that they either have very large Log-periodic beams or several different beam antennas.

Communications distances change on a cycle oriented on the daily solar cycle, on the 11 year sunspot cycle, on current CME [solar flare] conditions, atmospheric noise, and etc. and etc.

That being said there are plenty of rules of thumb and I won't discourage you from refering to good reference manuals on the subject - if you don't have the money to buy the books, why not try the library?  The General license manual has plenty of information on propogation as does the ARRL Handbook [and you can save $$ buying a used copy - 3-4 years old is not really out of date for a book that is printed annually]

Now, with that as a preface, let me give you a few tips:

For short range[0 to maybe 1000 miles] daytime communications on HF, use a dipole and 40 meters
For similar short range nighttime communication on HF use a dipole and 80 meters.

Best long range communications with wire antennas for me have been on 20, 40 meters [30 if you do CW]

That being said, there are days that 10 meters from here to japan is like a local call, and I've worked great distances on 80 as well, but it's not as 'easy' with a simple wire antenna - See "Low Band DXing" by ON4UN for details on how to do DX on the lower bands - it's the bible for that work.  He's got plenty to say about propogation as well, but mostly on 40 and down.

My American made dual mono block, class A 200 watts per channel power amp alone weights 120 lbs.  takes two people to lift it....and it cost as much as my FTdx-5000D and all is does is amplify audio signals.  And while you can hear my system clearly at 3 city blocks, the Yaesu is heard all over the world.

Thanks to Deming, the Japanese manufacturers learned how to make world class electronics worth in the market what they charge for them.

Since I'm using a tuner into a 160 meter loop, I always have to tune the tuner first - and what I have found with my AL-80B is that provided I'm close to 1:1 on the tuner, I can use my pre-set numbers and get so close as to not worry - these pre-sets all developed with dummy load and some on-air testing with dead bands. 

Anything that uses RF is going to be vulnerable to jamming in SOME way.

Drones must have an onboard backup plan which would be revert to Otto Pilot and then do [something - return to base, fly x direction, blow up, crash, whatever].

However, I'm pretty sure that the level of data encription used is something that would be very hard to crack which leaves simply blanketing the thing in RF noise and hope to force the S+N/N ratio to a point where the receiver no longer hears the commands over the shouting.

And, THAT being said, an anti-radiation missle would have one heck of a beacon upon which to home in on.

I would think that between frequency hopping, onboard computer systems and quality incription, actually taking control might not be quite as easy as people think.

Of course, I'm speaking here of the armed drones used by CIA/Military and their Ilk - I imagine the less expensive cop-type drones starting to gain favor amongs the police staters will be a bit easier to upend.

The truth is that nearly any speaker will sound better than the one in the rig!

Full range bookshelfs as noted are a good choice if it's efficient enough to be driven by your radio.

I bought a bunch of 5" dia. big-magnet general purpose speakers from a local electronics parts supply and built a wood cabinet to house them - they work well for me, but I've also used the MFJ $12 'clear tone' speakers which are surprisingly good for the price, and are ideal for mobile use.

The matching speakers do look nice but IMHO they are way too expensive.