Brake pads, and rebuilding kits, (seals) are totally obsolete parts in the aftermarket for those B body Bendix disc brake systems.
From time to time brake pads show up for sale on e Bay, but as you allready found out, you can't get them anymore at your local auto parts store.
Rebuild kits probably have been obsolete for 20 + years.
When i need pads for my customers cars, i send them down to this company to have them relined.

http://www.nationalbrakeservice.com/

You might not be able to safely use your car until you get your brakes working properly. Good luck.