I have a very large rotary tumbler. It is an 8” pipe about 30” long. It is an awesome tumbler with stainless pins. It does work with rice, but it is not nearly as quick or effective as a vibratory. It takes about 3-4 times longer to get similar results as a vibratory. If you are going with rice over stainless (which you should) then you should go with a vibratory over rotary.
I can’t remember who makes my vibratory tumbler, but it was not too expensive and works quite well. The store bought vibratory will probably cost less than building a quality rotary. Motor, bearings, shafts, pulleys, belts, pipe, etc. it ads up fast.
