I have just had a Milltek fitted to mine, and so far really pleased.
Nothing too loud but just gives a nice note when you put your foot down.
It is the non-resonated one I had fitted, so its not as quiet as the resonated one, which I feel would be too quiet.
Depends on what your looking for, most will only give a minimal increase in performance though.
I was looking at the Tegiwa single exit cat back but this came up 2nd hand so had it, then 2 Tegiwa's come up for sale after :lol:
I see your West Mids as well, so if you wanna hear it give me a shout