I am kind of partial to the Novi 1000 since I run one on my car. If you have any questions go to
www.superchargerhelp.com and ask around over there. They have message forums for the Paxton, Vortech, ATI, Powerdyne, and Roots/Twin Screw blowers. Really great for info. The older Novi 1000 that I am running can push 15psi, and it only cost me $1700 new. Something to keep in mind.
Chris