You mean caliper No 3 and No 5. The first is 180mm rotor on the front, 160 on the rear, the second is 160mm on the front and 140 on the rear.
Does the Rockman frame has a +20mm mount? If so, you'd need a 180mm rotor on the rear to go with your frame and caliper (no adaptor needed, only the 0.1mm shims to center the caliper).