Roger at
928's R Us carries the whole kit including the Audi tensioner that is needed with the set up.
He worked it out with Porken to be a supplier of a completed kit instead of just the bracket and installation instructions/parts list that Porken sells you. Those other parts you would need to get on your own to complete the job. that way you buy everything you need from one source and don't have to worry about the Audi dealer or auto parts store giving you the wrong stuff.
It's where I got mine from. Roger is a good guy, you'll like dealing with him.