I have made several Cattle Panel hoops coops and am making a 4th. I will attempt to document this 8x8 as I go along.
They are loosely based on Chook-A-Holics https://www.backyardchickens.com/articles/permanent-hoop-coop-guide.47818/ but I used 2x4's and added 2x4 field wire over the 1/2"...