Try calling them. I talked to them a while back; very helpful, and the woman on the phone seemed to know what she was talking about, withuot it being a REAL obvious sales pitch.
BTW- why do you want the drilled/ slotted rotors? Most street applications dont see enough heat to warrant the drilling or slotting, unless you are towing heavy in the mountains with no exhaust or trailer brakes, which is just stupid to begin with.
Daniel