Tangs can usually hold their own against most fish. I'd say just about any reef-safe fish (even those that are "safe with caution) would be okay. Dwarf or Pygmy angels are usually "with caution", but very often leave stuff alone. There are lots of reef safe wrasses, clowns, cardinals, hawks....the list is long. If you have not already, check out places like Bluezooaquatics or liveaquaria.com. Lots of ideas there.