An alternative to cattle panels would be concrete reinforcement sheets available at Home Depot, and other Centers. They are smaller, but can be attached together to desired size.
Just an IDEA to consider :old :idunno,,,,,,, and easier to haul home.
Another Center sells slightly larger. 4 x...
You can use one of these plastic sheds, and just install ventilation, windows, and pop door at bottom.
There are many options, but Pricey, compared to home built coops made from plywood.
These would need to be modified with ventilation, windows, pop chicken doors, and interior roosts, and...