I went down the custom route in the end, and managed to get a cat back and down pipe for £700 fitted, worked out about the same price as miltek but i didnt have to fit it and its completely unique.
If you wanted miltek, go on euro carparts website, log in then add it to your basket but dont buy it, after 2 or 3 days they send you a 15% discount code if you complete the order!
I have a milltek on my tfsi quattro. Prev owner had it fitted, but went with resonator option. It does sound good but a bit quiet. Ive decatted it now too, but going to be replacing that again with a custom made 3" decat + down pipe, and removing the resonators.
If it was me, I would have gone custom from the get-go. Better value for money