I buy that stuff from Harbor Freight. The small one I have is an air operated one. I don't spend a ton of money on this stuff as I am not a professional. I also buy the $14 electric polisher that I use for much of the polishing. I use the small 3" for the difficult to reach areas. I don't think there is any ONE that is the best... it just has to fit your budget and your method. I think the most important aspect for me is Meguiar's Ultra Cut. That stuff cleans up the ski in a hurry but it ain't cheap.. Good Luck