c'mon, damsels can be pretty cool and remember that clowns are a damsels. there are plenty of small gobies that will do great, as well as smaller mantis shrimp(excellent for monster lovers) some smaller blennies
t5HO lights would be much better than PC(even though a PC bulb is just a t5 bent in half) however there are no t5HO fixtures made under 24" except for an 18" model made by nova, however there is just a single parabolic reflector so the whole t5 vs. PC issue is somewhat obsolete unless you want to go through the trouble of DIYing in a few individual parabolic reflectors. if you don't mind the expense then a 70w MH + pc supplements would be great for a small reef tank and you could keep just about any coral you want, although for most zoas your current 2x18w would work. most people who are selling their 96w quad lights do mention temp. issues.
t5HO lights would be much better than PC(even though a PC bulb is just a t5 bent in half) however there are no t5HO fixtures made under 24" except for an 18" model made by nova, however there is just a single parabolic reflector so the whole t5 vs. PC issue is somewhat obsolete unless you want to go through the trouble of DIYing in a few individual parabolic reflectors. if you don't mind the expense then a 70w MH + pc supplements would be great for a small reef tank and you could keep just about any coral you want, although for most zoas your current 2x18w would work. most people who are selling their 96w quad lights do mention temp. issues.