I found these online while searching for lightweight rotors, they say they are 12lbs lighter than stock, for a total of 48lbs; $920 for the set, but I dont know if i can trust them. if these are legit than I may be seriously interested, but until then...
heres a link of they're sight
Brake Kits - Performance Pads, Rotors, Calipers & Brake Upgrades