trigger, puffer, and lions will all eat shrimp, crabs, and any fish they can wrap their lips around. may want to re-think those fish if you would like inverts. brittle stars are cool, and easy to care for. as for cleaning well they do eat detrius and are scavangers but as a cleaning crew probably not as effective as crabs, shrimp, and snails. try checking out compatablility charts on fish before you add anything together. then just go from there!
one fish, two fish, red fish, blue fish- Dr. Seuss