I may be biased but I'd recommend the Novi 1000. It flows better than the a-trim and almost as well as the s-trim. The 1000 can be pullied to a max of 15 psi so it has some room to grow if you don't like the 5-6 psi you'll get out of the box. I bought my Novi for $1698 and I think for the money, it's the best supercharger on the market. If you have any more questions about either the 1000 or 2000 check out
www.novipower.com the entire site is dedicated to the Novi line of blowers and has excellent information on it.