Several bolt-on options available: - AE101/111 twinpot caliper based conversion, cheap enough, about £300-500 depending on parts used - Wilwood kit: Available from Dave Burwash for around £800 I think? - Endless kit: stock diameter 6 piston caliper, £2000 I can get some spacers and calipers for the Twinpot conversion, all you'd need then is to buy the discs (about £100ish) and have them machined down, as well as a bit of grinding on the caliper bracket, oh, and longer wheel studs