Geoff,
you said that the 2nd turbo came in at 4k, but not with a rush. But then you say you want a Supra 'Completely standard inc wheels if poss, but NO other mods whatsoever'.
Don't get me wrong, but if you get one with the completely stock exhaust system with the cats still fitted, I wouldn't expect TOO much of a rush from that 2nd turbo.
Good luck with your search, but remember, if you can buy one at a lower price than the car is worth for its' age and condition, hence saving maybe a grand or two, you can make a great car out of it to your own spec. Even facelifts are up to 8 years old now. Most of them aren't going to be absolutely mint.