Looking to do a brake job on the tahoe, seems r1 comes highly recommended. Priced some drilled and slotted, not sure I need them, but I'd like the zink coating from their website. Went to Amazon and jist checked and it's saying the same set of rotors are like $100 less, but, it's not giving me the part numbers off of R1 website? Amazon says it comes directly from R1, any help on this?