I called ebc and they confirmed usr7512 is the correct size for the Z with sport brakes.
I notice this ad in the classifieds...
370z NON-SPORT F/R NEW EBC SLOTTED ROTORS AND POSI QUIET PADS
He has the usr7512 listed as non sport.
I tried reaching out to that seller to get some clarification but didn't hear back. Can anyone with sport brakes confirm that is the correct model rotors.