Im htinking about going w/ nitrous instead of headswap. After looking in the catalog Compucar has a kit for 4.6 for only $450 It is adjustable from 75,90,125. And then NOS has there 15o shot for $650. Which will be better. Is the NOS kit really worth an extra $200? What else do i need for nitrous other than a bottle warmer and purge kit?