Agree, upgrade to a dual circuit. With a spacer, you can likely run a brake booser as well to get power brakes like the later trucks had. From there, the choice is yours - you can either do front disk/rear drums or 4 wheels discs, with a proportioning valve in the rear line to make sure the front brakes lock up stronger. I don't think one approach is "easier" than the other. Front discs will look pretty much the same no matter how you set up the lines - my recommendation would be to go with the outer knuckles from a pre-85ish solid axle mini truck, a 1990+ FJ40, or a FJ60/62. The knuckle/disc swap is well documented here, and nets you bigger, stronger, fine-spline birfields, beefier steering arms, and disc brakes all at once. Plus, it uses "off the shelf" Toyota components. The "bolt on" wilwood option might be easier, but you're still stuck with weaker knuckles. If you plan to wheel it, coarse-spline bifields are a common failure point on the earlier rigs.
I went with FJ62 knuckles/discs up front, and the Chevy Monte Carlo disc brake conversion in the rear, sold by
@Poser here on Mud - not sure if he's still in the game but I believe the only "one-off" item needed in the setup is the rear rotors, which are essentially the Monte Carlo rotors machined out to fit the center hub of the FJ40 rear axle. My truck is a 75, so it was already dual-circuit/power brakes, but I've seen other folks on the forum add power brakes to the older trucks by either cutting the rib in the firewall, or installing a spacer behind the brake booster to push it forward of the rib - but fitment is often complicated.
