Hi, I'm lookin at getting some rs3 brakes so have a few questions, I see the calipers on eBay going for £200 to £300 which first of all seems very cheap, secondly I hear the rs3 discs won't fit the a3 due to different hubs on the rs3 so am I rite in thinking , ttrs disc and rs3 calipers is the route, also things like brake lines and pads am I best getting them from dealers?