I dont think the one in the first link is an sti intercooler, its a wrx one with sti painted on by the looks of it. There is one for sale on scoobynet at the moment although its not the best looking .
http://bbs.scoobynet.com/private-sale-gene...ntercooler.html
If you count across the number of rows on the one in your ebay link and then compare it to the one on scoobynet it looks like it is shorter. ( hope this makes sense )
I would avoid the aftermarket one and hold out for an sti one.