by the way, get a snowflake for sure, i just got one the other day and it is the coolest fish i have ever had. so pretty and active and fun to watch. i just need to get him to eat now....
most people would say you should have a bigger tank to go aggressive, but i think if you have a good skimmer and keep your fish count down a bit, you should be ok. something like this
sf eel
flame hawk
small puffer
dwarf lion or yellow tang.
that would give some color to your tank as well.
good luck