A turbo can match a supercharger off the line, given the revs of the car are raised for a sufficient amount of time beforehand, to give the turbines sufficient flow and time to wind up.
I might go a 6, they are pretty damn cheap. Although I do love the grunt of the 8.
I tried an VT II SS tonight which was an auto, and boy it was shocking. I'd have to rip that gearbox out straight away, it seemed to kick in too early, even when in "power mode" and was really clunky. Is this all of the auto's or just a problem with some, that might be thrashed? Or low on trans fluid or something?