Other Exhaust Options?

[3002 tii]

It seems like the only options for non-m z4s are stebro, milltek and supersprint but all of them are pricey. My old Audi cat-back was less than the price of just a muffler for the Z4. So I was thinking of getting a good quality but universal fit muffler, but need to know the dimensions:

http://www.magnaflow.com/02product/streetmufflers.asp?shape=5in.x8in.%20Oval

14815/6 caught my eye and was hoping to mate it to the Supersprint connector pipe:

http://www.eurosportdesign.com/pc-451-117-supersprint-bmw-e856-z4-30i-front-connecting-pipe-replaces-cat.

 

[Aebous]

I've long been on the fence for getting either a Magnaflow or Flowmaster exhaust. One of these days I'll drive into a muffler place and ask for a quote