The range is huge and is limited only by your imagination. Anything of western origin that catches your fancy can either be bought of the shelf or can be made for you on commission. An internet search will produce hundreds of retailers and commission artists.
When looking for getting art specially made to your design, search for not just dealers or manufacturers of western metal art, but look for the specialty areas like art relating to cowboys, ranch life, the Southwest, horses, the rodeo and so on. People who deal in these super specialty areas will be extra https://www.nahls.co.jp/ knowledgeable on the subject of their specialization and will be able to guide you in finalizing your design and the materials to be used. Having a bronze barn star painted black will never look as good as a black wrought iron one.
And remember if you come across metal sculptures of cowboys, horses and other things connected to the West, this is art depicting the West, but not western metal art per se as these are not traditional form of western metal art.