My fish bible tells me that a flame could fit in your 29 if it were alone, but I agree that, with the other fish already in there, it would be tight quarters.
If you are looking for a good little angel, try Fisher's angelfish, they barely get 3 inches and would be a good fit for you tank. You could also get away with a cherub angelfish.
Also, I like the royal gramma in your set up, it will stake out its territory in time and will keep other fish at bay, even your clowns. Best of luck to you.
-Dr Marco :sfish: