Very nice tank.
I know you said sps doesn't do well in your tank but have you tried stylophora as someone mentioned above? Super hardy and it grows crazy fast. Can't kill it. Comes in green, purple, blue, and a "rainbow" variety. It's my favorite sps.
Aside from that torches are great or maybe a frogspawn which should be able to touch the hammer no issue. Maybe grape coral, euphyllia cristata. I want to get one myself.