So I'm going to be making a planted tank for my betta once I get the cash (soon, in other words) and I know I want a small school of corys to handle things on the bottom of the tank. The problem is, I can't decide on which type of cory I want, and I don't really want to mix n match corys and hope they school. The ones I like the most are False JuliI Corys, Skunk Corys, and Peppered Corys. Any advice? Also, it'll be a 20 gallon long, so I should have room for 6, right?