A
sp. is your best bet, as these are small, colourful and don't poop too much.
They hide a bit at first, but once they settle down (after a month or two) they aren't shy.
Give them a dimly lit tank with LOTS of driftwood/rock hiding places and you will see them come out much more often, as they feel more secure.
They like warm (27C+), well oxygenated water and meaty food like cockle and bloodworm.
