Personally I dont think any of those fish would be sutible for a 5.5 gallon tank. I had ONE clown in a 12g nanocube and felt that that was too small for him even. My first tank was actually a 5.5 with a false back and I had 2 clown gobies in there, they seemed pretty happy plus they have great personalities and coloration.

As for an anenome, no way, they need big tanks, lots of flow, and strong lighting.