Re: fish, in my experience maps tend to ignore fish. Still, if you want to keep fish with him, go with something both harmless and expendable.
I have an Ouachita map about the size of yours and a tiny YOY stinkpot in a planted tank with a bunch of bluefin killifish, blackspotted topminnows, banded pygmy sunfish, single individuals of three or four other fish species, and two lesser sirens. I have had no fish losses, though the ghost shrimp population needs occasional replenishment (I believe the sirens are to blame).