I'm not sure about the cheapest place to buy a Blowzilla (you can try superchargersonline.com), but a buddy of mine sella a water injection kit that he put together (much cheaper than Kennedy's kit or Kenne Bell'
s kit). His website is
http://home.columbus.rr.com/dlasota
His name is Don and he's a wealth of KB knowledge, too. Tell him Cara told you about him.
Good luck! I am thinking of putting water-injection on mine. I also am going to relocate the IAT after the blower at the same time and get it re-dynoed.