I'm sorry, but if you're wanting a reef safe and invert safe fish, your choices will be narrowed down dramatically. I had to rethink my stock list for my 70 so many times. Each time I had a favorite fish that I wanted there was always stories of how it can eat small fish or inverts...fish that would seem completely peaceful. But I'm glad I researched the real behavior before experiencing it first hand. I really don't recommend you getting a damsel, they are very aggressive even with fish bigger than them.
A quite docile fish, yet beautiful IMO
, is a purple firefish. Or you could have a trio of zebra dartfish. Royal grammas look like some dottybacks and are less aggressive. They are a basslet too, so you can't have two, if say you wanted a chalk bass you couldn't have both. I won't be the tank police, but there are going to be people who are going to highly discourage from getting a tang that grows over a foot, let alone 2.
Garden eels are for experts really, they are very shy and not like other type of eels. Usually best in groups or species tank. I've seen them put in a tank with seahorses...that's how delicate they are! And 3-4 inches won't be a good setup for them, neither will the super aggressive fish you want to keep them with.