"Nori" isn't used for seaweed salad. It's used for wrapping sushi, or crumbled as a flavoring or garnish for sushi, sashimi, & soups. "Konbu", which is used to make traditional Japanese soup stock, is sometimes, but rarely, added to salads after it's stock flavoring job is done, but again, this isn't the best choice.
You'd be better off looking for "Wakame", "Arame", &/or "Hijiki", all of which are used in cooked & salad dishes regularly