Disc brakes (especially on the front) will make a huge difference over drum ... use good quality pads and rotors, and your brake fade concerns will go away.
GM used those 728A disc brake pads and 2-15/16" diameter single-piston calipers on a wide variety of applications including 1971-78 1-ton (8400 GVW) G-30/3500 Vans ... so they should be more than adequate.
NAPA 242-2000, 242-2001 calipers
728A pads are available in several different "grades", everything from organic to "severe duty".
They even used those same pads on the same application with the 10,000 GVW, but used a larger-bore (3-3/8") single-piston caliper.
This "interchangabilty aspect" does cause me a little concern, when it comes to the "value-conscious consumer" type that would throw a set of cheap organic pads on a 10,000 pounder.