IMO for that many birds you would be best getting a shed kit from a big box hardware store and modifying the shed into a coop...
Stores like Menards not only sell complete shed kits but they also sell all sorts of cut corner shed building kits, like brackets or even complete wall structures...
https://www.menards.com/main/buildi...ldings-outdoor-storage-accessories/c-9482.htm
Of if you have the skills they even sell plans like this https://www.menards.com/main/buildi...altbox-shed-building-plans-only/p-1489425.htm said plans also have a bill of materials so you can simply buy all the materials go home, build and tweak into a coop pretty easily...
And last but not least there is probably a shed builder in the area that has sheds on skids that they will truck in and drop on your property, then you can tweak...
Just some ideas to get you going...
Stores like Menards not only sell complete shed kits but they also sell all sorts of cut corner shed building kits, like brackets or even complete wall structures...
https://www.menards.com/main/buildi...ldings-outdoor-storage-accessories/c-9482.htm
Of if you have the skills they even sell plans like this https://www.menards.com/main/buildi...altbox-shed-building-plans-only/p-1489425.htm said plans also have a bill of materials so you can simply buy all the materials go home, build and tweak into a coop pretty easily...
And last but not least there is probably a shed builder in the area that has sheds on skids that they will truck in and drop on your property, then you can tweak...
Just some ideas to get you going...