There are several types of anthias that would make good candidates, squamipinnis, Tuka, bartlets & dispar to mention a few. They are reef safe and very colorful. Most anthias seem to like the company of their own kind, groups of 3 and up often work well.
The blue reef chromis (chromis cyaneus) is a nice schooling fish too. They are not as common as the blue/green chromis and are very hardy, attractive and typically not aggressive.
Fish generically referred to as "dart fish" can be neat as well. The blue gudgeon goby, bar goby and sissortail goby are pretty nice fish that do well and hang out together. I especially like the blue gudgeon gobys, very pretty and peacful fish.
I'm sure others will have some additional good ideas....
Joel