Racing Brake makes a kit to swap the ccb rotors to standard iron with aluminum hats, while keeping the calipers. They don't list the price for the rear rotors, but the front are around $1600/pair. My guess is the rears are slightly less, so probably $3000 total.
https://www.racingbrake.com/RB-2pc-r...-Ir-p/2472.htm