I personally would try somewhere like tps and get a genuine belt. Not saying that the others are rubbish as one of them make it for Audi but if something was to go wrong you might be in a better position to argue with Audi and get some help in fixing your car.
In my last golf the cost of a genuine vw belt, pulleys and water pump from TPS was only like a tenner more expensive than buying pattern parts. Originals lasted 100k so went with originals and they were still going at almost 200k when car written off by a blind Audi driver.