OIK, an 8 inch diameter buff is about 2 foot circumference. Taking Brian's figure of 2750 FPM for the outside of the buff means it should be spinning at around 1300-1400 rpm. StewMac's buffer has 14 inch wheels and turns 715 rpm, that gives a buff speed around 2600 FPM, again, right at Brian's target.
I have a cheap buffer with 8 inch wheels that turns 3500 rpm, it works but I have to be very careful with it - I have burned into lacquer with it. Certainly 2000 or 1800 would be better, and slower would be better yet - I don't have enough experience to say if you'll have problems with 2000. This guitar is KTM-9 buffed on the wheel and there is a little flaw about half way between the neck pup and the waist - it is almost impossible to fix something like that. Not a great picture, sorry
Another option that works pretty well are the foam pads for a drill motor. Instead of using buffing compound you can use automobile polishing compounds. If you are only going to do one or two instruments that can be cost effective. I've use them with good results on both KTM-9 and nitro.