with 6 hens you'd want 2 or 3 boxes. I'd go with three incase chicken math plagues you. As far as where to feed, I personally prefer outdoors, but with our freezing winters it tends to come indoors on particularly cold days so it doesn't freeze as fast. It just tends to get the feed and the coop...
I'm jealous as well. Ours is built but we're residing with reclaimed barn lumber, adding functional windows and painting the interior it will be like a new coop when we're done.
I am so jealous of you getting to work on your coops. I got my 8' x 8' ice house early this winter and although it works for now, it's just not how I want it. Unfortunately the temps are consistently in the teens and there's 3' of snow, Will be awhile. We will be residing it with reclaimed barn...
Here's mine! It's 4'x6' and houses the golden girls (Sophia Pecktrillo, Rose Egglund, Dorothy Zbornchick and Blanche Nevercreaux) and four of their friends (Tessie McGreevey, Queen Camilla, Spyro and Greycie Blue).