After you drive his, plan on getting one for yourself.
My personal preference is Vortec. the transmissions are quieter, and you can call them and buy any part for them if needed. Prochargers sound "angry" with noise even at idle. They wont sell you as much as a screw for one. Any problems with the unit will leave you without a blower for as long as it takes them to fix it. Sponsored cars get front of the line service, as regular paying customers wait... and wait.
I've found that serp belts are fine for about 10psi. Beyond that, go with a cogged belt. Beyond 20psi, get a support strut for crank and blower nose if you want reliable belt life. Or go with a front drive tran$.

9:1 is fine on gasoline.