3.4 I guess
Supercharger is good but the 7th injector is really expension and they aren't tuned well. Turbo can have more usable power if they are set up correctly. I like turbos over superchargers...its all in your setup
That's a fairly tricky question, and it all depends on what setup you choose, what power level you want and the operating RPM range. Either are and can be made applicable, but most likely there is a supercharger kit offered in the aftermarket.
as well, you have to choose your budget... more power=more money necessary