Hi Stu
Instead of buying off the shelf exhaust why don't you find a place that makes exhaust systems. You can then tell them what you want i.e how loud, single or twin exit tail pipe.
I've done the delete on my OCTAVIA diesel. It has helped reduce back pressure and the turbo spools up quicker. Looking to do the same on my A4 convertible but it has 2 rear boxes so will be about £200. Will have to wait till after the new year.