With enough good quality live rock your tank will not cycle. Fish can be added the very next day quite safely.
Dont use a fish to cycle as its cruel. why put the fish through the oreal of ammonia burning its gills and stressing it to the point of death when a simply prawn from the fridge will do exactly th esame job?
And dansels are real pains, they are very territorial and will not tollerate other fish in with them once they get settled, (as aquascaper about remvoing damsels! he is going through the ordeal of hte century at the moment)