I'm building a 60g cube, and still considering if I want to put a screen top on it... just so that I can add wrasses, dartfish, and dottybacks to my available fish groups (jumpers).
A pair of clowns is kind of a requirement, for me anyway. I just added my first fish, a pair of ORA snowflakes, last weekend.
Concentrate on gobies and blennies, perhaps cardinals, if you like them. Some of the bassletts would work, chalk bass, for instance. Dragonettes, if they're eating prepared foods, would work. I'm going to have a hawkfish, at some point, but I want the tank fairly mature before adding one.
Some Chromis and Damsels would be OK... I wouldn't want one, but they're OK
With the right flow for SPS, you're going to want to stay away from clingfish and pipefish, (and seahorses). Too delicate for high flow.
Eels are probably out too... 1st, they'd eat the other small fish that would be suitable. 2nd, they're likely to end up on the carpet.