Personally, my first pick would be an 04-05 gtp comp-g. the comp-g has the upgraded suspension and 3.29 gearing instead of the 2.93. Plenty of aftermarket support for the gtp (you'll see countless threads on here about that). If you had to, you could also look at an 06-07 GT which despite the name has the same supercharged engine as the 04-05 gtp (L32). Only bad with the 06-07 is a tune is hard to come by. For whatever reason, they can't be tuned, but there are tricks to get past it. Like these guys said, there's not as much aftermarket support for the GXP, but it sounds like maybe a few more options are on the way for them.