What kind of 29g? 30"x12"x18" high, or a cube?
I had a SB in a 29g. It was my first non-damsel fish, so I'm kind of partial to them. That said, I'm not sure I would have put a second clown in it, there wasn't a ton of swimming room.
If you don't want to go with the percs or ocels, look at skunks.