I use a SunwayFoto DP-39 on mine. Excellent build quality and provides a very secure connection with my Markins screw-clamps and my RRS lever clamp. Sized perfectly to not look out of place on the bottom of the camera.
I also use a Sunwayfoto plate on mine (the 60mm version). I have RRS gear for my digital equipment, but the Sunwayfoto stuff I have my Rollei setup (also have a 60mm screw release clamp) is very well made. Since the plate is universal (don't think RRS makes a Rollei specific plate), and Arca Swiss plate will do.