I bought mine on ebay from SSautochrome. If you do the same, make sure to open it up and make sure that the wg spring is the correct one, I bought one that was supposed to have a 3.63 psi spring in it, but when i opened it, there was a 15psi (big red) spring in there!! I emailed them and they sent me not only the 3.63 psi spring, but also a 5.6 psi spring really quick.
I have to say thier customer service is second to none.(really)

 

nice intercoolers, now good service, damn ssauto's puttin in some effort latley or what