I am also in the process of trying to figure out what the best setup for drum/drum power brakes is. So far I have found that most master cylinders for drum/drum brakes on our trucks are the non-power type (they need a long push rod). I recently bought this master cylinder (
http://www.summitracing.com/parts/aaz-10-1363). It is a Cardone 10-1363. From what I can tell, it is a drum/drum master cylinder with the shallow push rod bore for power brakes. I have yet to install it to see if it works.
I'm really not sure if there is a difference between drum/drum boosters and drum/disk boosters. From what I have read, there isn't a difference. There is only a difference in master cylinders.
Good luck!