I would suggest an LE5 N/A to start and boost it later. That way you have the best ECU in a GM vehicle (E67) and should you decide to boost you have a great starting platform. You can either purchase EFIlive or find a tuner shop that has it to remove the VATS and other module interfaces.
Though I have to say; I just helped a guy with an SR20DET swap into a Datsun Roadster and when all was said and done we ended up swapping out the stock Turbo for a smaller compressor and running with some ebay ECU. It put 240 HP @ 12psi to the ground on a dynojet and ran very save A/F ratio.
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-Adam Chant
SCdyne Performance Engineering
"Tune it or lose it!
TEAM SCSKYSC 2008
I don't know..?