Yeah, mine was for dirt/compost sifting. It was a commercial dryer drum, that ran off a 1/2 horsepower air conditioner motor, and was made to be high enough to put a wheelbarrow under it.
For the purposes you are looking at, you want no holes in the basket, and both washers and dryers have holes. For most applications I can think of, low to the ground is a definite asset. The height of mine was a problem, lifting things up that high hurt after a few minutes.
If I wanted a tumbler like that, personally, I'd start with a dryer and put a removable barrel type thing in it. It could be sealed tight (rock tumblers are watertight, I suspect some of your needs would want that too) and removed for messing with.
If I were experimenting with it, I'd put a tightly closed 5 gallon bucket in a dryer and see how it works, so you know whether to scale up (to use the space better) or down (a bunch of one gallon jars packed in tightly might be more effective) or whether a dryer motor won't turn it. Don't forget where the shaft comes in on the back, that's the center of pivot, and it'll have an easier time turning things that center on it in a balanced fashion than it will turning something with the weight on the outside edges and loaded asymmetrically. Packing things in with towels or blankets etc would work well, and be easy to change as needed if your containers change.
:D