S3 set up calipers, carriers, discs and pads, I upgrade the brake hoses for Hel hoses but the standard hoses are fine.
Discs are 310mm vented over the 286mm solid discs, and the piston in the calipers is slightly bigger but I can't remember specs. You don't need to change the hubs.
Not sure why the Scirocco needs the hubs I thought they would be the same.
To my knowledge the scirroco R is a step up again, with the disc being 335mm(ish) and vented, I know the hubs make for a wider track