Both rams and keyholes don't eat plants, And I haven't heard much of angels eating plants either. You could do some mollies, rainbow shark no, maybe a keyhole or two for cichlids, but I wouldn't recommend another breeding pair. I like the black skirt tetras personally, and though zebra danios are small they could probably outrun any fish in that tank. No neons, as mdfrookie said, but some bleeding heart tetras, some rosy barbs (not tiger barbs, they get too aggressive) or some cories. I agree with mdfrookie on the dwarf pleco, so maybe a bristlenose or a rubberlip would work.
