After posting to you I googled "wholesale dried seafood" and got many hits giving the impression that, if you order online, you get products sent from abroad. I am wondering if you may need this information for research purposes, in which case you might contact whoever is sending dried fish maws into the US and ask him where the predominance of US customers may be found---perhaps retail outlets here.
The products you describe would, in the United States, probably be found in an Asian market. Big concentrations of Asian markets would be in the Chinatown neighborhoods of San Francisco or New York---San Francisco also has a Japantown. In Canada but near the US border you would also find many Asian markets in the Chinatowns of Vancouver or Toronto. In Chicago I have seen a lot of dried seafood in the Vietnamese/Thai commercial neighborhood around North Broadway and Argyle Street. If I could choose just one of these places to shop for Asian dried seafoods I would head for San Francisco. Good luck finding what you want.