The coral beauty, damsel and clarkii clown stay at one end of the tank.
I don't think a single MJ 1200 will cause so much flow in a 55 that it will interfere w/ the fish's swimming abilities, or two or three 1200's for that matter. If you always feed in the same place this can be an issue, as Melosu said, or if the flow always takes food to the same place. I've seen automatic feeders recommended to people in the past to get fish to explore more, and act more naturally. I plan on trying one out myself soon, but I don't have any direct experience yet. FWIW I started varying the sides of my tank I feed on, and that has helped some.