Stay away from the Yellow-tail damsels. They can be terrors and are hard to catch when you figure out how rough they can get. Some alternatives: Bangaii (Banner) Cardinal, Pajama Cardinals, Royal Gramma, or Chalk Basslets. If you really feel the need to do damsels I would go with the Yellowbelly Damsels, which are quite a bit more docile than the yellowtail. Your setup looks great, I wouldn't sully it with damsels.