Well, the spotted climbing perch will eventually grow to 6" and it requires live foods to thrive (such as fish), so nothing smaller than 3" should go into the tank. Angelfish mix nicely with Climbing perches, and they're alright with RTBS, Giant danios should be alright, Tiger barbs, Rosy barbs, Red glass barbs. Those are just a few that come to mind. Some nice plecos (Royal, candy stripe or even clown pleco) would look nice aswell.
Hope this helps,
Ryan