i was just gonna say go with the highbanded goby and a pistol shrimp. They form a really interesting relationship. What types of corals are you planning on keeping? What about Black Percs? They are really pretty and they aren't that common. You could always try the Coral Beauty or Flame, but it's taking a long shot. I've heard where the flames destroy clams and corals. Then you get that one nice little angel that does perfectly with all corals. Hmmm....too bad they couldn't screen those out for us huh? I'd love a flame angel in my 40, but there is no way I'd risk loosing my corals. =( Or hey, cut a frag off, set up a small display tank put the flame in there and see if he's interested. I've heard of people trying that before placing them in their main display. Bi Color will get too big. You could always try a black capped basslet. They are pretty. I believe they stay small too.