I dont think you could go wrong by getting a newer body style s197. My buddy has an 06 gt and the thing is nice. Yeah the car ways at least 500 lbs more then my fox, but you also get a lot nicer ride. I love the fox bodies but when it comes down to it, sitting in the new one and then sitting in the fox body... there's no comparison. The fox body is pretty simple and has not too many features, no cup holder for gods sake! Anyways if you can handle taking a drive in a new s197 and knowing that youll see at least 10 more on the street when you go somewhere then go for it. Plus it sounds like it is going to be one of your only rides... So having a couple options and a cup holder might not be so bad!
By the way, I raced my old 89 5.0 GT convertible automatic with 3.55s, full exhaust, air kit against his 06 GT hardtop and he pulled away from me with no problem. Now I have a 90 GT hardtop manual which I believe would keep up with him.
Either way man, the foxes are nice and are becoming very rare, and the new ones are cutting edge but very plentiful. It seems like these days your not going to get to much respect unless have a special edition s197.
Lastly I just wanted to throw this out there. If you sold your maixma you could fix up your 5.0 completely. Throw in a 6 speed
tranny (help a little with mileage), supercharge it, and probably build the engine (heads, cam, intake... so on). I would respect that choice more then any other. Another suggestion is that you could even consider buying a 03 04 cobra for about the same price as the new body style. The difference is about 100hp.
Anyways, hope this helps!