Nitrous Kit Recommendations?

I'd go with NOS http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/Powershot.html
and get there Power shot system 125HP (non adjustable)
OR there Super power shot system. It's adjustable from 100HP, 125HP and 150HP I wouldn't go over 125HP until you get forged pistons though.