Funny enough Ess5ive and myself were only talking to APS today at the Castle Coombe VW & Audi Track Day and they hinted on looking at the exact same conversion. I've offer up my car to be left with them for a couple of days in mid August to see if it can be done, will keep you posted
Looking on ETKA; the ceramic discs from the R8 and RS6 are £1925 + 17.5% VAT EACH!!!!
Much cheaper to go down a upgrade with a big brake company i think.