Okay, so I'm getting a 15 gallon column tank set up (This one in the link) for a community tank with, for certain, 1 male Betta and 1 Oto. I was originally planning on 2 albino cory cats and 2 upside down catfish, but after doing more research and thinking about the size of my tank (with 7 live plants and 2 decorations that double as hidey holes) I decided to change this to 3 of one or the other. I'm not really sure which one would work best however and I would like some well informed opinions and suggestions.