How about a t-post and wire run enclosed with a tarp over 1/2 of it. Then you can get some tree trunks and fit sideways in the corners for roosts. I saw someone that had rubber maid containers with holes fit in them for night protection one time and then she had one of those three drawer rubbermaid cabinets with the ends cut out for nesting boxes.
For my brooder I use an old dog octagon enclosure and the door fits an igloo type dog house. Maybe something like that would be on Craigslist or freecycle?
I picked up 2 new (unexpected) chickens tonight and used my husband's dog box to make a temp coop. I put some chain link I had laying around under it so nothing can dig in and used a drawer out of a tupperware stacker as a temporary nest box.