you don't need to built a supra, just keep the stock 2jz-gte motor which has proven many times that the stock bottom end can handle power of up to 700+RWHP bone stock... with stock twins @ 20 psi, intake and exhaust is almost more than enough for someone who wants to experience what a supra can do.

Couple of guys (joe and chris locally that I know of) have gotten low to mid 11 second passes on stock twin turbos... but it depends on what you like - i like the idea of the 240 although nobody has given me a ride in an SR swapped 240 yet!!