I'm looking into a Cobra brake upgrade, and I found some cross drilled and slotted rotors on ebay for cheap. I'm just wondering if these would be better than/equal to the factory Brembo rotors that come with the Ford Racing kits? I know the differences in performance between cross drilled/slotted and plain rotors, I'm just concerned with the quality. The part numbers on these are RXS61044 / RXS61045 #40.