After a bit more research.. a few more questions:

Has anybody experience with centerlock disc rotors with Avid brakes? Shimano obviously says use centerlock rotors only with Shimano brakes...
What rotor brand did you use?

I could find Avid rotors on CRC in 185 (Shimano apparently only has 180...).
The only 203 I could find was from Shimano.

Do I need a special tool to install the centerlock rotors? Got the impression but couldn't find any conclusive information.
What is it called? Any shop recommendation?

Thanks
Sascha