A pair of captive-bred orchid dottybacks generally make excellent additions, as they are stunning fish. It's worth repeating, though, that many people here hate them and consider them to be aggressive and obnoxious. I've never seen that with any of mine, but lone anecdotes have to be balanced against wide-spread reports of bad behaviour. I still think that this aggression is probably more common in solitary fridmani placed in tanks with few or no places to hide.
Coral beauties should be okay in a 40g tank, but only if you have lots of live rock. They are, like all dwarf angels, grazers, and need to pick at live rock all day.
Striped (fang) blennies are heavily underrated. They're great fish, being both personable and hardy.