I'm in a similar situation. My DSS Pro Bullet 306 with AFR 185s has around 1600 miles on it now and I'm ready to order my s/c. I have 8.7:1 compression and all along I've had my mind set on a NOVI 2000. DSS said my particular app could easily handle 15 psi, which should easily make 530 or so rwhp.
Paxtons are relatively easy, no I haven't installed one yet, but there is no intercooler to mess with so that makes it easier right away. The general thing I've heard is that if there's one thing that sets the Paxtons apart its the brackets. They are simply the best design and the strongest. I met the owner of this site, I believe his name is Dan, at the Ford 100 Year Anniversary Celebration in Dearborn, MI this weekend and he showed me the Paxton he has on his car, and explained to me how easy it is to put tension on the belts, and how belt slippage simply isn't an issue.
Considering you can now get NOVI 2000s for around $3000 satin and $3300 polished from musclemotors.com, there's no reason not to pick up a Paxton. Thats just my opinion though, there's no doubt that Vortech and ATI are good also, but let me close with this, what was the first supercharger ever offered as a FACTORY option on Mustangs in the 60s? Yep, Paxton.
Good luck!
