You can get a Truvox Orbis 200rpm rotary in a Heavy Duty version, that is where you can add weights to take the weight of the machine to 40kg (normal machine weighs 32kg). This is only available on the 17" version.
Speed is 190rpm, which is just about spot on.
The motor is offset against the direction of the rotation so you have the best balanced rotary scrubber / polisher on the market, in my opinion (heavily biased as well!).
Standard machines (17" 200rpm or 400rpm) are available from £449 + VAT inc drive board or scrub brush, the Heavy Duty version of the 200rpm machine is available at £599 + VAT.
Simon