You need semi metallic brake shoes. They will increase stopping ability a great deal. I had a real hard time finding true semi metallic shoes last summer, and now I can't find them again. But this link does list them, and it is about what I paid for them. It would seem that the normal auto parts store, even for the cheapest to the premium, just don't work for a darn. When you get some true metallic shoes, you will definately notice the difference.

http://brakeperformance.com/brake-shoes/Premium-Brake-Shoes.php