I am getting baby chicks for the first time in a day or two and am planning on getting a coop for them by April. What size would comfortably house 6-8 hens? I will be buying dual purpose hens more than likely. Also, I want to raise them as organically as posible but cannot free-range them 100%. so am going to consider a portable pen as well. What size would be good? Any advice is greatly appreciated! Thanks!