Well, I have to say I think there are too many choices for this!
Spoke to AKS today, had a good chat and talked about some good solutions. Particulalrly new Brembo (DB9) calipers and AP full floating discs.
My next car (in some time) is likely to be a Mk7 R. So I'd like to be able to take at least all the expensive stuff from the Mk5 brake kit to that. If that looks like it's not possible or there's still significant expense in getting those parts on then it may be more prudent to spend more modestly now whilst getting the job done and my current problems solved. When it's time to sell the car I could have it taken off so the S3 parts can go back on and then sell the BBK on it's own for an equally modest loss.
As I said, there's so many hardware options it's a bit bewildering!
TTRS calipers were also talked about, some secondhand ones maybe? Wary of Ebay for stuff like this. On the subject of these, I'm sure I heard that Audi had issued a recall on these brakes??
Have I really got to spend £2,000????
Any further suggestions very welcome!