Yep, Mgamer's got some good CPD's for sale, cheap. You could put 5-7 of those in there and that'd be nice.
4 or 5 freashwater dwarf puffers would work also, and they are fun to watch.
I do believe that puffers need more room than that...........
sorry ment to type 2 or 3 beings they only need 2-3 gals per fish and love a planted tanks adult size is 1 inch and best kept around 80°F and would keep under control any snails that might be on the plants, and won't eat on the plants.4 or 5 freashwater dwarf puffers would work also, and they are fun to watch.