I'm currently looking at a second hand Brembo GT kit and need some info to make up my mind. Unfortunately the kit comes with the drilled discs, which appear to be crap by most accounts..

I've read all I can on these forums, so please bear with me if these are stupid questions:

1 - Compatibility: can calipers & discs of different brands generally be assumed to be compatible if they are the same size? Ie: do some discs of x size have different horizontal offsets from the wheel making them incompatible with calipers made for the same size disc but a different brand?

2 - Is it possible to somehow mount the Brembo GT kit (323mm) to the standard (312mm) discs? For example by using a custom carrier? Or would this be inadvisable due to the curvature of the bigger calipers?

3 - Can other calipers (ex: Brembo GTs) provide noticeably better heat dissipation? I'm sure the choice of discs can make quite a difference here, but was just wondering whether calipers can affect how easily your fluid boils...

The reason I'm looking at these options is the standard discs are pretty decent for most applications. I would just like to replace the calipers on the front at least. I'll make a few phonecalls tomorrow to compare stock S3 (312mm) and stock Leon Cupra R (323mm) disc prices. Maybe using the drilled Brembos till they fail then switching to Cupra discs is the way to go...