A "stand alone" motor is pretty handy for the Beall buffing system. I built this one using the original motor from my lathe when I changed over to variable speed. I even reused all the switches and controls on the new buffing station. It's 1 1/2 hp, which is a bit overkill, but I used the motor I had. I can tell you that a 1/3 hp motor will be a little underpowered for this purpose.......and that's what I used in the beginning. My guess is a motor of around 3/4 to 1hp would probably be ideal.
The large buffing wheels.....I believe they are 8"......are the most overall useful, but 4" is mighty handy, as well. If I were to suggest, I'd say get all the accessories you can afford, because you will use all of them eventually.
For larger work, the mandrel extension is a good item to have, too. It will give you the clearance to comfortably do your polishing.
Some time back, it was suggested to me to get some of the rubber stretch gloves that doctors use......this is a superb suggestion, and the reason for it is getting a good grip on the bowl to be polished. I bounced a couple of bowls on the concrete shop floor.....man, that really is disappointing to lose a bowl after all your effort!
ooc