I agree, looks like a Red Belly and channel cat to me, but I'm no expert on either. Either way you will probably need a much bigger tank in a year or two. Nice tank, though!
I have a Blue Channel Catfish, and the brownish catfish is a Salmon Catfish. I have plenty of time before I have to upgrade. I have a 55 on standby at my brother's house. I always raise baby fish and grow them up and move them and sometimes sell them to pet stores for new rarer fish that can be hard to afford.