You might not realize it, but those are basically shackles, used for all sorts of rigging applications, on boats and otherwise. The shape of what you show is specifically a bow shackle. Stamped sheet steel ones are mostly made in only small sizes, and are more likely "D" shackles.. Larger ones, likely what you need, are usually forged, cast, or made of formed wire.
I think you'll find something to work. There are at least hundreds of manufacturers, and probably tens of thousands of suppliers.