I am going to build my first coop as soon as I get the plans drawn up and the lumber bought. I am making it 5ft wide by 8 ft long, and was wondering how many chickens it will hold. I'm thinking maybe up to 20? The assortments I want to get from McMurray Hatchery all come in minimum batches of 25. Will my coop be big enough. I should have 8 nest boxes in there when everything gets built.