What kind of corals do you plan to keep?
Will you be able to do special needs (like feeding 3x daily for anthias)?
I would say a tang or two and a harem of anthias/wrasses would be a great addition. Pygmy angels are great, but all have a pretty decent chance at nipping corals (save for Genicanthus sp., who are more costly deep-water fish). Gobies are always great if you're into details (there's a lot of subtle beauty to be had in reefs compared to the giant fish of a FOWL), as are invertebrates. They can add a lot of personality. Cardinalfish (kauderni, orbicularis, nematoptera) are very interesting due to their shape and behavior. They will school, spending most of their time suspended still in the water column; they breed relatively easily and the males hold the eggs in their mouth. (Note: if you decide to get kauderni, get them tank bred. They're a little more expensive, but adapt better to captive life and are on the verge of endangerment in the wild.)
As far as pest control goes:
- Zebrasoma tangs (yellow, purple, sailfin, etc.) or [slightly less desirably] Ctenochaetus tangs (tomini, kole, etc.) will graze just about any kind of algae off your rocks.
- A six-line, four-line, or yellow coris wrasse will keep pests (flatworms, etc.) and other critters like bristleworms/polychaetes under control. (Note: some bristleworms are bad, some are good. Most eat detrius and waste food, some eat corals and eventually inverts/fish.)
- Mandarins and rainfordi gobies keep your pod population under control (both are really beautiful fish and require an established tank... That said, pods are a good thing but mine are so rampant that they coat the glass).