I would say use 1\4 inch angle wich you can buy cheap at tri star steel they sell it in 20 foot lengths I'm not sure how much I know 1\8th inch is around 22 dollars for 20 feet
I would say use 14 inch angle wich you can buy cheap at tri star steel they sell it in 20 foot lengths I'm not sure how much I know 18th inch is around 22 dollars for 20 feet