Reef safe fish suggestions for 90 gal sps

[Cubeman]

I'm looking for fish suggestions for a 90 gallon sps dominated tank (with one LPS - Open Brain). So far the only fish are a Hectors Goby and a Canary Wrasse. I'm looking for fish that will swim out in the open but will remain small (max 4-5 inches). Would prefer a herbivore (but not mandatory)with zero possibility of coral nipping and musn't be territorial.