Steel
They can do cutting. Costs about $40 per hour. Need to find what tolerance they can do on cut length.
Probably will not use but also find the cost increase if using COR TEN steel. Weathering steel, also known as “COR-TEN” steel, contains up to 21% of alloying elements such as chromium, copper, nickel and phosphorous. The alloys form a protective rust patina which reduces the corrosion rate with time. COR TEN steel tends to be cheaper than stainless steel. It is a bit harder to weld and corrosion is likely to occur at the welds.