Sure or any of the Chinese shops. The really basic ones work just as well as the expensive ones; they just might not last as long.

I've had basic Aroma ones currently have a nice Korean one. I'd say the quality is vastly different between those.

The high quality Japanese or Korean ones will be pressure cooked and cooked in a way that allows it to stay warm in the cooker for days. Not a single grain of rice will be stuck/inedible. If you get the cheap rice cooker, it'll burn, cook unevenly, go bad if left overnight in warm mode, etc.

If you eat rice 2-3 times a week, get a Zojirushi or a Cuckoo.

I don't think you should leave your rice in a warm cooker overnight because it could develop bacteria.