Also, if my current dummy load won't support having 180w fed into it for long periods of time, and it's a dry dummy so it likely won't, I'd have to complete my wet dummy load project. I have everything except the resistors ($50) and the mineral oil ($20). So, an additional $70.
Where did you get the idea that the SB-102 has an output power of 180 watts? The SB-102 does not produce 180 watts output. The 180 watts you are referring to is "180 watts PEP INPUT" not "Output". The SB-102 final amplifier cannot and will not produce 180 watts output.
$70 digital frequency counter (I really don't feel comfortable with the way the analog tuning on the 102 is set up)
If you are thinking that a Frequency Counter, by itself, will provide you with a "Digital Display" of the SB-102's operating frequency then you are mistaken. Adding a "Digital Display" to the SB-102 is much more than a "Frequency Counter". The dial accuracy is quite good in the SB-102, providing it hasn't been messed with. The VFO in the SB-102 is all solid state.
The way the HP-23A power supply is wired, it would be easier to simply buy a power supply kit from oldheathkitparts.com and use that in place of the original electrolytics and resistors. So another $70. You see how this adds up quickly?....The problem is with the way it's wired, you can't just snip out the cans and solder in new ones.
You can rebuild the HP-23A power supply with individual parts for less.
You can restuff the 4 tall black capacitors with inexpensive snap in capacitors.
Mouser cap replacements:
150ufd 450VDC (snap in, replaces the 125ufd 450VDC cap)
Price: $5.20 each (4 required).
Caps below the chassis, also from Mouser:
20ufd at 150VDC (Axial lead)
Price $3.77 each (2 required)
40ufd 450VDC (Axial lead)
Price $6.58 each (1 required)
Diodes, also from Mouser:
Price: 14 cents each (7 required)
total for parts is $35.90 plus shipping to replace all the HP-23A power supply components except for the power transformer and choke. That's "half" the $70 price you said you would have to spend for a "kit" of parts.
If you don't know how to restuff a can capacitor, the following link will show you how to do it.http://www.ppinyot.com/C/capacitor_stuffing.htm
Replacement belts all 3 of them are being sold on eBay under auction #321047628064 for $5.64 and that includes shipping.
If you ask around I'm sure you can get the 11 pin male and female plugs/sockets and hoods along with sufficient multiple wire cable for a lot less than what eBay sellers are asking for the plugs, hoods, and wire "kit" ($29.99).
I don't know what cabling/equipment you are referring to when you say "cabling and equipment to hook it to my current system" other than coax cable and PL-259 connectors.
The manual, if purchased from one of the various manual websites, will cost about $36 which is normal and you will need it not only to setup and operate the SB-102 properly but also to service the SB-102. i would not recommend you attempt any servicing of the SB-102 until you have the complete assembly manual.
I understand fixed income under SS but I'm sure there are hams who can help you with obtaining the parts.