I am using Shimano RS-805 calipers with Shimano SM-RT86 "Ice Tech" ISO 6-bolt rotors.
The RT86 6 bolt rotors are not as nice as the RT99 centerlock rotors. They don't have the same cooling fins. Nevertheless, they are a high-end XTR level component.
The rear required an SM-MA-R160D/D adapter to fit a 160mm rotor.