We had a presentation on nano reef aquarium's maybe a year and a half ago. the ultimate fish man did it and it was good. At BCC if any locals here can remember. I first want to shoot down a couple fish. the mystery wrasse too big and too active. would swim circles for months and never be happy. some of the smaller dwarf angels might be ok but this would be pushing it and none are truely that reef safe. no butterflies at all. No big puffers but the small ones are ok and not reef safe. catalina gobies are cool but need at least 10 degree's less. you can find them in the pacific ocean around LA. Hence "Catalina Island". the ones in the hobby I believe are from mexico.
Really to sum it up.
1.when looking for a fish I think fish of color- bright colors,yellow, blue, orange, so on.
2. then to I want an active fish or hiding. your active swimmer like clowns, wrasse, damsels ect. the ones you might not see. some gobies(they can borrow behind rocks.) rabbits can be shy, some angels, ect
3. ease of care, feeding, waste, hardiness
4. price
5. rare-cool