Very hard to bend an 8' panel and keep it's shape without extra t posts or securing to a wood frame. You are better off creasing it at 4' and making an A frame.
Just for fun, a bowed 8' panel set in a 4' frame creates a 2 1/2' high run. Is a 4' wide run of value? A full 16' panel set in an 8' frame creates just shy of a 6' peak. Stretch it to 10' and it's just over 5'.
Just for fun, a bowed 8' panel set in a 4' frame creates a 2 1/2' high run. Is a 4' wide run of value? A full 16' panel set in an 8' frame creates just shy of a 6' peak. Stretch it to 10' and it's just over 5'.