While this isn't the best tumbler, it is a great starter one. Rock tumblers can get very expensive, so I suggest you start out with this one to see how you like it. This is also a great gift choice.
This next tumbler is the "I want a better tumbler but don't want to spend hundreds" kit. It's also supposed to be much quieter than other options.
So you've decided to get the big one from the entry-level tumblers. This one comes with a few extra items and has a big capacity, but don't expect it to be as quiet as #2.
This big boy has a 15lb capacity. If you plan on selling rocks like I do, then this is a good start. It's about as loud as you can find on amazon.
I've personally never tried this style, but if you like it, let me know.
Grit Pack #1
This here is 3.5 Lbs of polishing grit, in 5 different grits. Just like with sandpaper you move from the lowest grit to the highest.
Grit Pack #2
Here you have 7 Lbs of polishing grit, but this time it's only 4 different grits. You'll still get a smooth finish w without the plastic pellets, but it won't be top-tier. It's a better price per pound.