Try looking in the phone book
under "wire rope" or "slings" or "rigging". A call to a local crane company can also help steer you to a good local supplier. Here is a link to an article that might help you understand the different types of chain. triple B, proof test, grade 30, grade 40, and high test, All chain is NOT created equal. Whatever you do don't buy chain that is not stamped with it's respective rating. There is some cheap chinese crap out there that isn't worth its weight as scrap.Find a good supplier that knows the difference between different grades of chain.