You can use an external tuner with the 746, just make sure you disable the internal tuner. Otherwise, the internal tuner will "chase" the external tuner as you adjust the external tuner and damage can result.
I use an external autotuner (LDG AT-11MP) with my 756ProII and it works very well. The AT-11MP has a much wider matching range than the ProII's internal tuner. The AT-11MP is rather noisy when it is tuning, but it tunes quickly and you get used to the noise pretty quickly. It will interface with the ProII with an optional cable and you can use the Tune button on the ProII to activate autotuning in the AT-11MP. I'm not sure offhand, but the AT-11MP may also interface similarly with the 746.
Jeff, KC1MK

I have used a number of HTs over the years, and so far my favorite 2-meter HT is the ICOM IC-02AT. They're no longer made (haven't been for quite a few years), and in comparison to newer HTs, they're large, heavy, don't have any bells and whistles, only 10 memories, and don't offer wideband receive. However, they're very resistant to intermod, sensitive, and rugged. Given their limitations, they're definitely not the HT for many people, but I just wanted to mention them as a reference point.

I usually use my ICOM IC-756ProII when I am operating QRP from my home station. I used to use a Kenwood TS-850 for home QRP operation. (I use a Yaesu FT-817 for portable QRP operation, and occasionally from home as well.)
73,
Jeff, KC1MK

I'll second the opinion that the Product Reviews information here can be very useful. You can often get further information and comments on a particular piece of equipment by e-mailing the person who wrote a Product Review.
The FT-897 looks like a nice rig, but I usually avoid a radio that has just been released. If there are any bugs or consistent problems, they usually surface and are often corrected in the first year or so. FWIW, I have had an FT-817 for almost two years, and it's been a great rig for portable QRP operation and I have had no problems with it (not that I would recommend a QRP rig as a first radio for anyone).
Depending on your budget, there are some good deals on used equipment. In particular, the Kenwood TS-850 (HF only) and the IC-756Pro (HF + 6 meters) seem to be good deals nowadays.

Alex,

With the rig in USB mode, adjust L41 (the TCXO adjustment) for a frequency of 51.200000 MHz at TP8. If you look at the rig from the top, L41 and TP8 are on the PLL unit. If you need a picture, e-mail me at the.weight@verizon.net and I can scan in a drawing and send it to you.

If you're interested, check out the TS-711 group at http://groups.yahoo.com/group/ts-711/.

73,
Jeff, KC1MK

I have ordered from Heil Sound several times, and not only have I been very pleased with their products, but Bob has always been very helpful, answering my questions and providing information very promptly. It's a pleasure to deal with a company with good products, excellent service, and someone as knowledgeable and as pleasant as Bob.

I too have dealt with George at Gigaparts on several occasions, and have experienced consistently excellent service and support. Their prices are very good also. I now make all of my major equipment purchases from Gigaparts.
No connection with Gigaparts other than as a very satisfied customer.
Jeff, KC1MK

I have ordered from Morse Express three or four times, and have been very pleased every time. Marshall was very helpful providing information and answering my questions, and I received all of my orders very promptly.
I have always found it a pleasure to deal with Morse Express. BTW, I have no connection to Morse Express other than as a satisfied customer.
73,
Jeff, KC1MK