Coral banded shrimp are primarily carnivores... so I would recommend mysis, plankton or other meaty foods. When we had a coral banded, we never actually fed it directly. It would just always come out when we fed the fish and pick up the leftovers.
Just make sure some food gets to him once or twice a week and he should be ok. Some are killers of fish. Usually the fish will be dying anyways when it happens. Some i've heard go after them regardless.
Usually if you feed them a small piece of food once or twice a week that should be sufficient. They're not that difficult to keep just watch your salinity and you should be fine.