Get 5 corycats and a dojo loach. If your want something active shoot for the dojo loach. I have 3 corys in my 20gal and I love them. I also have a RN pleco (not that active IMO) and a Gold dojo(who is the crazyist thing i have seen).
if you wait another few weeks (2-3) the plants can root better and this way the plants wont be floating all over the place once you add your new bottom fish in