f150 engine driven compressor

Lookin at buying the kit from sd or lowriderdepot... anybody know of alternatives to what they sell? seemed like a good price, but i'm new to air and not sure what's the best way to go...

http://suicidedoors.com/products/airmanagement/engine-driven-kits/97-03_ford-f150-v8-engine-driven-kit.htm