Brakes from the TT-RS and that platform will directly bolt on, if there are any available ceramic brakes from the OE.
Brakes from the RS4, RS6, R8, Lambos, etc. fit, but require different carriers. Same for 17z, 18z calipers like those found on the Tourag and Cayennes, etc. I would say that if you found an Audi ceramic kit, you might need to fab new carriers, otherwise you can pretty much run any brake kit that fits your hub/rotors/wheels.
If you are serious, you should probably start looking at platform sharing between VWs and Audis and see if the sizing etc. fits