The Spyder II is based on a Professional Product lower, where as the Spyder is a E'brock Vic Jr or Super Vic.
The install is easy, if you need help with the rail set-up let me know is is very similar to any other aftermarket rail, the clips are different however.
I'd run a Spyder on any healthy NA, N2O or Boosted combo they make awesome power. Vic Jr for the small cube or high TQ combo's, Super Vic for the high reving or large cube crowd.