Look into getting stuff from CX Racing, they have the best Ebay intercoolers and piping. It is where I got my stuff from and I am very happy with the quality, and the pipes welded nicely.
As far as performance of a cheap intercooler vs expensive goes, it is fairly un-noticible. I have seen Ebay vs. Spearco tests in the past and the results were very close as far as HP differences. You have to ask yourself: is the extra 600-700 bucks worth it for the extra 5 HP? Remember, you can almost always turn the boost up one more PSI and re-coup that.
I got my intercooler and piping from ebay. My guess is lots of the turbo guys on here did to. Some of the couplers are really cheap and the clamps aren't the greatest, but i never had a problem with mine. Actually plan on moving from 2" to 2.25" and will probably buy all the pipes from ebay again, though I may get some nicer couplers and clamps.
Got an i/c if you need it
