Who drills front brake drums????

Anyone in America or Canada have any of these? I would like to know what they are off of to start with since all a bodies with front drum brakes had the small bolt pattern from MaMopar as far as I know. Heck I don't know anything so teach me here.
My car has 10 inch drum, 4 inch bolt pattern brakes. I was referring to the brakes for 100 and 125 dollars. I want to buy some.