The 6M XL FLAT PACK CONTAINER STORE – GALVANISED is an excellent option to a conventional 20ft shipping container, built especially to achieve a similar space and product of galvanized steel as opposed to corten steel. You should note flat pack containers can only be joined in one direction eg: https://wood-effect-storage-boxes91345.ttblogs.com/10558527/not-known-details-about-new-20ft-shipping-container