I have a 55 gallon bowfront tank with 1 Raphael cat(full grown-8-10inches), 2 corys(full grown- 4 inches), 2 bumble bee cats(full grown- 3 inches), 1 blue gourami (full grown- 6 inches), 1 pair of turquoise rainbows(still growing-at 3 inches), and some otos(tiny guys-big appetites). My question is what other fish could I put in this tank? I would love to have some more middle or top swimmers, but I'm having trouble finding something tough enough to withstand the gourami's attitude. She rules the tank. Also, will need something big enough not to be lunch for my Raphael cat. Any suggestions on possible tankmates would be helpful?