For small gouramis you might want to look into Dwarf, Robin and Honey Gouramis.
How about getting some frogs for your setup? African clawed or african dwarf like fully aquatic conditions.
Kuli (sp) loaches are also a little unusual.
Upside down cats look a little odd, I suppose.
Glass cats look incredible if you get a bunch of them (8 or so).
I know they're not fish but what about shrimp? Or a crab that can cope with fully aquatic conditions such as the fidler crab. Don't keep crabs if you've got any other bottom dwelling fish or critters (Shrimp, frog, plecs, loaches)
Can't think of anthing else... Sorry that they're all bottom dwelling.