Hi kedster,
R&S Mattress in Salt Lake City have mattresses that are made by Brooklyn Bedding (they are owned by Brooklyn Bedding). They would be somewhat similar but not the same as their Amazon mattresses. Some of the other Salt Lake city options listed in post #2 here would also have both types of mattresses available but you would need to call them to find out the specifics because I don’t know the details of what they all carry.
Phoenix