you should go to the power adder forum for this one.
it all matters in what you want. Strip car street car, both, top end, low end. I mean i would go with either the procharger or the vortech. Hoever for that low end torque at like 2200 rpm then go with the kenne bell. However it cost much more then the centrificul vortech and procharger.
I'm a big fan of the Pro Charger systems. As a matter of fact I almost did a Procharger ATI 17/14 setup with a 3 core intercooler....mmmmmmmmmmm. But spray is a lot cheaper . If I were to do a blown car I'd probably go with the Kenny Bell Twin screw setup. They are a lot more efficient from what I understand. It all depends on your goals.
if you have the money procharger, it makes more Hp, with the intercooler , 50-100hp more @ 10psi, and you can run up too 15psi, on the stock block/cr., insted of 10 like all other non-intercooled S/C