I got a cheapo one from Bezoson and for its purposes it works fine. It was from the Magnasonic brand. It's 20oz/600mL total size, so it can fit a small ash catcher - stems are no problem. That said, I do not recommend mine.
Because of that, I actually do have some things you should watch out for.
First is being aware of the minimum fill capacity - mine mentions possible risk of damage if it's not filled to the minimum. I haven't experienced that sort of issue, but I also am worried to find out. It also happens to be quite a lot of alcohol, which I wish I had realized beforehand. If there were a smaller one for screens I may have opted for that one, although it is handy to be able to clean stems as you mentioned. Also, mine may not technically suggest alcohol as a fluid to use. It does get warm but I wouldn't say hot. Definitely do not have open flames nearby, lol. And have a fan with other ventilation.
Second is being aware of the finish / paint on the Ultrasonic Cleaner. Mine very smartly (/s) came with some kind of paint which melted when introduced to alcohol vapors. I must have spent an hour getting a bunch of it off, and didn't even get all of it so that was a nice surprise. It also is important to check how they empty, for example, if you just have to dump the liquid out of the unit and maybe it drips down into the display buttons, or the paint.
Third and maybe finally, they also plug in, so you may want to have a space by a sink with an outlet nearby. Mine also happens to be quite high pitched and as loud as the devil pissing, so you may want to have that sink with an outlet be in a bathroom behind a closed door where you clean your equipment. Or a kitchen where you live alone with a room you can close and hide in.
Okay fourth and finally, mine happens to have a timer set for up to 480 seconds (about 5 minutes). Not bad for quick cleans and it tends to get the job done in that amount of time, but I mostly have only used it with screens. The few times I have cleaned my glass stems in there it takes maybe 2-3 rounds to get them sparkling.
Were I to go for a round 2 on an Ultrasonic cleaner I might try and opt for one with a removable liquid container + removable basket. I would double check the noise and see if it's present across all options. And I would definitely not get one that has a painted finish. The fact that it plugs in can be annoying, given that you have to empty it, so that may be something to consider as well if there's no removable liquid dish. Whether or not a device with some variation of all 3 of these exists, I'm not sure, but it would be pretty close to the perfect one from my experience.