Any fish without flashy colorful colors will do and isn't similar to a Betta like a Guppy.
Don't put Bettas with Fin-Nippers because Bettas don't fight other fish that aren't in their Target list so your Betta could get hurt.
Well I think they take time to rest for a while and stay put in a area for a while when there's peace, I don't think you can detect if they're sleeping because they don't have eyelids but when I see my Neons Resting, their colors get dim and they swim in place - I think it's a habit of their...
Betta Fish are cheap and cool, you can Keep them in a small Bowl if you're as evil as I am. But I still recommend you putting your betta in a large Bowl.
All you need is
Bowl or a (Small or Larger w/e) Aquarium
Some Bottles of Fresh Water.
Food (Betta Pellets)
-x-
Not necessary But:...
a Small...