just curious if anyone has tried any combination with the rs-gt's.. they are fitted on a b5s4.

You'll have no issues with disc size in terms of radial clearence, but you'll have to space out the wheel for the caliper.

The spokes cut back quick on those, so a 355mm or 370mm kit are going to have caliper/spoke issues unless you space them out (5mm to 10mm depending on kit/rotor size).

You'll probably be fine with a 332mm kit and I"m assuming stock is fine.

My experience was with the 2 or 3 piece ones in a 19x8.5 on a B6 S4.