I would like to have 5 blue chromis, two black clowns, 2 purple firefish gobies, a six line wrasse, 2 Bangaii cardinals. I already have a few snails and corals. In which order should I add these fish? Also is it possible to add one more fish as the centerpiece of the tank? If so what is a good one for a 55 gal reef? I like the flame Angels but I know they are not reef safe.