sounds good
I have a pair in a 55 gallon, also, and they do really great together. I have actually thought about throwing another female in there, but the two do so well together that I don't want to complicate things. I am sure that one male and two females in a 55 would be fine, though. I have found that as far as enclosures go with adult Crested geckos, bigger is better. It is good to have a lot of foliage and places for them to hide, as well as things to climb on. I wish you luck!