What fish you go with these?

I have a pack of 4 upside down cats the lounge around, 3 fish that resemble hatchets that are about half and inch long with a black marking dominating the back half of their body and have and orange tint (if you could name these that would be helpful as they were recommended and i wasn't given a name) a glass catfish and a rainbow shark. i want something that will liven up my tank as most of them just sit around (it is a forty gallon than that is an est 30x20x12 in tank)