Novi 1000 is a gear drive and the SN92 is a ball drive. What that means is the Novi 1000 you can pulley upto 15psi and the most your going to get out of a SN92 is 8psi but was really designed to produce only 6psi. A lot of information can be found at www.superchargerhelp.com
Thats alot of difference in the levels in the boost. If you found the sn92 cheap enough, then it might be worth it, but other wise, it seems clear that the novi1000 is a way better choice.