For your 318 or your golf?? if the 318 why is there a picture of the golf there? if the golf, why is it in the e30 forum?
If for the e30, the absolutely best way is a custom system modelled of a one of the performance-brand ones. Borrow someones, or get some detailed photos and take it into an exhaust shop and get them to fabricate one. A bunch of people i know all got together and got a dozen made and it worked out far, far cheaper than buying a name brand, and they were at least as good if not better.