Your in the same position I was in. I got a 55 gallon thinking I could add the yellow tang and found out my tank was too small. But just think, the foxface can get bigger than the tang. So I have decided to go with smaller fish with bigger personalities. So far I have a maroon clown and plan on adding a dwarf angel. I think the royal gramma would be a good fish, and a goby would be great too. Dont get upset with not having the tang or foxface. The smaller fish are just as much fun.