Royal gramma is definitely on the list, been looking into wrasse but I hear tons of issues with them jumping out even with a lid. I have a custom egg crate lid I made. I do have a pistol shrimp already in there I found it finally. So I may try pairing it with a goby, seems interesting.I would stay away from tangs with a tank that size. Have you considered a royal gramma? Nice colors and would love living in that aquascape. A cherub angel would be a really nice centerpiece fish for a tank your size. Bangaii cardinals are a good open mid water swimmer. I have a yellow coris wrasse which is very bright and active, will hunt your pod population tho. Benefit is it will take care of some pests if they get introduced on coral frags. And you can't go wrong with a goby pistol shrimp combo, that's probably going to be my next addition.
Regardless of what you decide on make sure you do a bit of research of the specific fish on your own before purchase. Even a quick Google in the store just to confirm is helpful.