ANY TSI air box will work...except the grille adapter/inlet might be different....but that is only a $6 part from the dealer
So look in the classifieds for a MK5 TSI (GTI/GLI) airbox, a MK6 GTI air box, Tiguan, EOS, etc.
Just saw one on Golfmk6.com for $70 SHIPPED though
But I don't know how you're going to make an intake out of the stock box though.
You can just remove the stock box & throw a coupler and/or a filter on the end of the stock MAF sensor if you really wanted to do a "ghetto intake"