some nice pictures here! you must have a quality camera and some skills to use it lol.
I really like that mirror koi, but ryan is correct, you have coldwater and tropicals and brackish water and freshwater fish in here.
keep working on the tank, it looks great already. think about where you want to go with it, what type of water you want to keep here (brackish, coldwater fresh, tropical brackish/fresh) and work the fish choice around that.