We've got the coop built but have not put in the roosts or nest boxes. For our laying flock of 10-12 we are planning 3-4 nest boxes, but aren't sure of proper size or the height to place them at. I've heard 12"x12" for box size. Is that right? How high up do I hang them? And how high do we put the roosts? Oh, lastly we plan to keep two roos. Can the roos bunk with the hens, or do we need to portion off an area of the coop just for them?