Most of the tumblers out now are the vibration rather than the old round and round tumblers. The new ones are faster. I've got a Lyman but most every one has their own brand...probably all made by same outfit.
I would just get the best deal on one from reputable company. And I think I'd start with some
treated walnut. Treated corn cob works good too, but doesn't last as well IMHO.