You said not super fast growers right? I would do fungia (I have a vivid neon orange one that I love), Euphyllia, acans, Platygyra, and maybe a trachyphyllia or lobophyllia. I would stay away from duncans because they can grow really fast, but at the same time they look great and they're in such high demand that you can just frag them and sell them or give them to people