I wrote about this stuff in a braking thread. The rotor is near unobtainable, or it was anyway. Anither member here and at the other forum hooked me up and iirc shipping was as much as the rotor. (Thanks buddy!).
If you search my threads you should find the info.
This rotor is 320mm, and was a nice upgrade with the master over the SV Racing Tokico and Nissin caliper bracket upgrade I helped get done. At a minimum, the 4p cal is a great and cost effective mod.