I'll just post the obligatory comment that IMHO, I think you should start with a MKIV Supra instead of the MKIII ;-) I've owned both, and if you're wanting to do a project car, the MKIV will be easier to mod, and will handle more HP than the MKIII. Too, parts are still readily available for the MKIV. The NA version of the MKIV's can be had pretty cheap - probably not as cheap as the MKIII, though.....
I'd also consider speaking/emailing Arnout over in Holland to get his views. He's taken a MKIII Supra as far as anyone.
Another consideration might be the MKII Supra, which is even cheaper than the MKIII, and a lot lighter. Put a 1UZ into that, and you'd really have something! Reg Riemer up in Canada is the expert on that vintage car.
