[mr_alberta]

There are certain tangs that will work for you. Some of the smaller ones such as Kole or Scopas or Yellow may work.

Most butterfly fish are not reef safe for one reason or another, but if you really want a butterfly, the safest candiates IMO are the Copper Banded Butterfly or the Pyramid Butterfly. Keep in mind that Butterfly fish often are difficult to feed.

If you have a lot of crabs/shrimps, etc., then that rules out Triggerfish, though some are reef safe-ish (like Blue Throats, Crosshatch, Pink Tail, & Sargassum).

Some angelsfish may work for you. Being in a mixed reef the safer large type of angels would be those in the Genicathus family (Bellus, Swallowtail, Lamark, Watanabei).