This is interesting, I've thrown around this idea in another topic but didnt get nearly as much response...
To the OP, check out kameari products...
www.zccjdm.com
kameari makes a 3.2L stroker crankshaft.....
kameari also makes a 89.5mm forged piston...
I really want to see a 3.2L L28et... the only 3.2L l28 I have heard of is NA...
As far as the twin turbo setup goes... I disagree with you there, would be better to get a MASSIVE single turbo and upgrade the valvetrain to hold 10k RPM's to make good use of the boost it could push.
Another Idea I will throw out on your build, you might also want to look into a SuperTurbo setup. A superturbo setup is where you have both a supercharger and a turbo. The supercharger would be so you could get boost right off the line till the massive turbo kicks in...
A Superturbo 3.2L L series that can rev to 10,000 RPM's....