I would suggest you look at different areas of your tank and different swimming styles and go from there. A scooter dragonet, shrimp goby or jawfish for the lower part of the tank. Clowns, wrasses etc. for the water column. Blennies, etc. for a percher.
Also, think about color and behavior. And what you like. Since you have a brand new tank, I would suggest finding a single fish that you are absolutely in love with and building your stock list around accommodating that fish. You have a lot of options with those tank dimensions. If you go with all small fish, you could have quite a few.
Good luck.
