Probably best to throw out your tank size, and name a couple fish you might like to keep. Then people can advise which ones they think would be a good match, and what a good combination might be.
Number of fish, or inches of fish per gallon is an arbitrary useless measurement in my mind. A 5" bar goby could be one of a couple fish in a 30 gallon tank. But a 5" hippo tang would be a whole bioload-worth for that tank, and because of it's behavior it would only be suitable for a tank at least three times that size, regardless of bioload.