What is involved in the swap anyway?
only way is to use cabrio/estate 4 stud hubs (I'm sure you need to change the brakes set up with calipers and the largest 4 stud are 280mm)
I believe if you convert to 4 stud the biggest discs you can fit are 280mm, so that would be the end of your 1.8t dream 
Not really, 280mm set up on good quality discs and pads will be fine.
Standard on a mk4 1.8t is 288mm only the Anni's (180bhp) got the 312mm set up.
