I have a Jet 1 hp in 1725, and a Baldor 3/4hp in 1725......the Jet came from a local outfit during a "sale", and the 3/4hp Baldor came from Pop's Knife Supply many moons ago.
If your thinking of anything faster than 1725, you need to re-think it! Early in my knifemaking career, my first buffer was a 3600rpm Baldor, which I purchased because it was cheap.....it nearly killed me on a couple of occasions! The very last time I ever used it, I lost control of a blade, the buffer literally threw through it THROUGH the shop wall and out into the back yard...there was a hole in the wall that I could put my fist through. I unplugged it, unbolted it from the bench, and gave it away a week later.
Most folks have heard the horror stories about high speed buffers....and for good reason. They are nothing but traps that maim or kill.