I tried to dig up the old thread, for continuity, but I couldn't find it. I dove back into the brakes today.
The short version: Use a double diaphragm booster with large bore master cylinders
The long version: Thinking that my brake booster was bad, I swapped it out and installed a double diaphragm booster in its place. Wow. Instant brakes! The truck stops without the pedal going all the way to the floor and it even stops when in low range. I think that as the pads get broken in, they will grab even more. I'm happy. Definitely money well spent. It doesn't stop as quickly as my FSJ, but it's also heavier, too. It'll be nice not having to give my leg a workout every time I drive the thing!