I have a maroon clown and he is very tame... They are aggressive if another clown is added, but he lives with other species of fish without any issues. Actually the others are a bit aggressive towards him. All he does is sit in his anemone not bothering a soul.
I have a Royal Gramma who isn't aggressive and likes to sit in LR, so a small tank wouldn't be a issue. I'm not selling him, but it would make a good choice for a addition if it were me.