There are many inexpensive light tents on Ebay. From the US, I do see US sources, but you may see something different. I don't know how shipping would be affected, but if from China, probably not at all.
Not too small is good advice, but you may want one with a front baffle. The purpose of such tents is to prevent reflections of room objects in shiny subjects. Instead, the point is, the featureless white walls are reflected, less a problem, not recognizable. The worst of these is usually the reflection of the camera (and the dark front opening, and you), so a smooth white front panel with a slot for the lens can be a good thing.
Lighting is not really the purpose. I just mean, you can do as well with any diffused lights, like umbrellas, and if you have that, the tent really doesn't offer an advantage except for the reflections. And if no tent, then no size limitations.