In the Nano forum, people should be happy to answer any question about Nano Tank setups.
Plan ahead, so you can keep things that are happy together without having to give up things you really really want to keep in your own tank and don't overstock.
I perfer clownfish cuz they make sounds to eachother.
They work best if you don't add other fishes to the same tank because, they will guard, their favourite spot if any other fishes are around. If left alone, you get the chance to see them dance around together in every part of their territory (your tank) in the evening when the evening light setting is on. During the daytime they mostly guard their turf and chit-chat together.
If choosing to host clownfishes, notice that some species swim in up&down movements and others swim from side-to-side, so you get some that move in the way you like best.