[hatzie]

The Diesel models and the 1 tons got hydroboost. The boosters should still be available for a lot less than $600. Get the pedals with the booster. IIRC the brake booster pushrod pin on the pedal is in a slightly different location on the hydroboost trucks.

The power steering pump is the same.
The booster has three lines. Pressure in from the pump, pressure out to the steering box, and return.
The pressure line runs to the brake booster then continues to the power steering box.
The returns from the booster and the power steering box run through a Tee back to the power steering pump.
If you're adding a cooler it goes in the low pressure return lines between the Tee and the power steering pump reservoir. Get a used cooler off a T800 chassis in the boneyard.

The PS pump to booster will need to be a hybrid with the LS pump fitting and hardline section on one end and the squarebody brake booster hardline on the other. I'd get used hoses as donors and get a hydraulic hose outfit to crimp the proper length of high pressure power steering line between the two sections of hardline... again much less than $600.
The booster to steering box line is a squarebody part.
The return lines are SAE J189 hose with constant tension band clamps or Oetiker clamps. The only exciting piece is the Tee fitting off the steering box. Source this from your 80's squarebody donor.