I thought about adding a marroon clownfish to my 30g... I decided against it and went with two teeny tiny true percula clowns - they swim around all day within 6 inches of each other at all times. I don't know how big they get, but they certain explore the entire tank constantly and are very active. I'm very glad now I didn't go with the marroon clown.
I like my purple firefish a lot too. He has lots of character and is a very unique fish. Only problem is he keeps kicking up all my sand to the powerhead above his "den" he made. Bright colors and very pretty aswell.