There's a member on clublexus, but the name Phil who wrote a how to on converting over to a TT,
the manin thing he has is the wiring diagram, that's pretty helpful for witing up the 2jzgte to the sc300
2.2crx:
you best bet is to had a NA-T kit
the NA-T supra's run pretty well some up to 600hp
so there's really no need to swap out the entire motor.
the 2JZ-GE is a pretty solid motor itself, only thing missing is the oil squiters used to cool the cylinders (but thats over kill in the GTE motor)