Try A3 machines, look under floor polishers. I'd prefer a slow speed around 150 - 175 rpm. Ours is a 17" Victor which i've found to be bullet proof and is now into dog years old but still keeps going. The CRB has all but replaced the rotary in most circumstances for us but for black top the rotary always comes out for a good scrub and you can post bonnet to speed drying.