Pictus cats prefer to be in groups and, in my opinion, are far too active for the dimensions of a 37 gallon tank. I would recommend cory cats. Personally, I think it would be better if you dropped the firemouth, did a pair of dwarf cichids, a good size school of tetras, a school of cory cats and bristle nose pleco.
I was assuming the OP meant angels instead of the other ciclids. A pair of angels in a 37 shouldn't be a problem. A tank with more depth would be nice, but I don't think necessary. However, a pair of rams or one of the other dwarf species would allow for more options of tetras and would be easier on bioload. That's the route I would go if it was me.