Im looking for a pair of 12a rx7 engine rotors

A good pair of 12A rotors will be hard to find. Best place to check would be RX-7 Club. Make sure you get the right ones for the year motor you have. They made different weight rotors which require different counter weights.

1976-82 vs. 1983-85

Also the rotors should have the same letter stamped on the side if they are a matched set. they need to be the same number (A-E). It is okay if they are one letter off so an A and a B together, etc but not ideal.