What are the dimensions of your coop?  If you are putting a bantam in b/c there will not be enough room for an other full sized bird, I fear that you are going to have an overcrowded coop.  If you are buying a manufactured coop, you CAN'T go by the recommendations of the manufacturer re: stocking density, as almost all manufacturers misrepresent their product.  You will need at least 4 sq. ft. in the coop per bird.  If you live in the north where winter weather will keep your birds inside much of the year, you will need even more space.  If you ever intend to replace aging birds with younger ones, you will need more space.  Ever intend to have a roo?  More space also.  I strongly recommend that when starting out you understock your coop.  I also agree that crested birds do better if in a flock of their own.  Same with bantams.  Do you live in an area that gets much snow, or much spring mud?  I avoid feather footed birds like the plague b/c I don't want birds dealing with ice or mud balls on their feathers, and dragging extra stuff into the nests.