id ay teh best options for the tank would be a nice group of shellies, multies or ocellatus would be nice, a pair of julidochromis would also work, dwarf south american apistos would be ok, shellies would be the best, theyll love the sand, maybe 8 then some danios or rainbows to take up the the top of the tank, they have loads of persoanlity, really are great fish you wont regret it