Early in my career I was very privileged to have been a regional manager for an attachment manufacturing company. During those years I rapidly learned there is a solution for every material handling situation. It comes down to analyzing what is required to pick, transport and deposit definite materials, what type of location will the materials be picked from or deposited into or onto, and will the material be handled from rail cars, over the road trailers, racks or stored at ground level on runners? Space available plays a big part in how you handle any stock. You can contact us via http://www.hovair.com/products.htm to get air castors and other load moving equipments.
There are numerous methods to handle flat, round, and angle materials, and it appears you are already using material handling equipment and ideas. Lift trucks with forks are by far the best and most reasonable approach if space is not an issue.
Special side loaders have been designed similar to lift trucks.
These utilize a mast and forks from the side of the chassis and need less space, but storage of materials in deep reach areas may be a problem with heavy weights. The side loader equipment makes best use of floor space; for example you do not lose as much storage space to wider passageways as for a conventional lift truck design. Then there is the idea of utilizing overhead cranes with specially designed magnets or clamps to handle the steel shapes.