Alex - AP already do a disc kit for the R32/S3 it has the bells and bobbins all included. About £500 if I recall.
As mentioned they do normally come with alloy hubs these things which mitigates the weight a little bit. My point being is that they are what they are and they cost what they cost. Its been discussed before about putting expensive discs on iron setups - its fairly pointless.
I just cant help think the money would be better deployed elsewhere, have a read of the NQS BBK thread which is the most read thread of 2010 and the third best read thread in the sites history - Its generated a lot of interest, I think the reason it hasn't been more popular is the fact that theres some effort involved in sourcing the calipers and getting them fitted, give me 4 pots on lighter 312's over single piston Audi rep mobile brakes anyday and repmobile brakes over 312's
The R32/S3 setup is convenient and bolt on and readily available, it is what it is and it does what it does for reasonable money, dont expect too much of it and its a great affordable setup thats good value, once you start trying to improve it you quickly get into the realms of diminishing returns.
Tom had good results with M1144's and the grooved or drilled disc versions add aesthetic/performance benefits when pressing on but you've pretty much hit the development limit with them by doing these upgrades.
That said Ive done a J hook version but I'm practising what Im preaching and feeling a bit embarrased about asking 200 per pair, maybe I should put a Tarox sticker on them
