I eventually went with a 1/2 hp mill motor and Lovejoy spider connection on the shaft. I have been as happy with that as any upgrade I have ever made to my brewing equipment. That was done probably 8 years ago....I replaced my, poorly operating, old mill with a Monster Mill and this motor, and agree with ynotbrusum, it is a valued part of my brewroom. I consider it one of those "buy once, cry once" purchases. There have been zero problems, and that's a huge improvement from what I had before.
Brewbama is right, it is "big enough."