^^^ the being covered is a fairly key question.
Personally, it might be good to let it mature a bit, but ultimately, go with something that will work, but that you will enjoy also.
Personally I'm afan of large groups of small fish. I'd personally look at microrasboras, small tetras, small/pygmy cories, otocinclus, aspidoras, or dwarf shrimp.
If you don't want a large number of fish, maybe 3 or so dwarf/pea puffers, or scarlet badis, assuming that you can get live food for them.