I spent some more time looking at your pics. Every single thing on the original truck is done poorly! In the rear, i recommend you use your existing rear axle. The perches on the new one are too short, and the e-brake is not done well. I would use your existing brakes (the drums work fine), and later, after it's all up and driving, take on the disc brake swap as a separate project. You need to weld perches anyway, and on your existing axle it will be easier and you know you will have a working e-brake. Remember that virtually every organized run with a tech inspection requires a working emergency brake.
The high steer arms are probably usable. That saves you a bit of cash right there, but have someone familiar with that set up make sure they are not the cast arms that Marlin talks about
Marlin Crawler
I am not familiar with All Pro's older stuff and can't comment. Their new stuff looks bomber.
The drag link and tie rod do not look usable at all. Toss and get new. Don't mess with questionable steering components.
On the front axle, you need to start over. New perches, new shock mounts, new brake line mounts, knuckle rebuild all of it. Do a cut and turn. Use the diff with arb and the inner axles/longfields. Use whichever housing is cleaner. I would cut off all the old work by the previous owner. It just is poorly executed and unworthy of a nice build up.
This would be a good time for 6 stud knuckles. At least consider it.
The shocks are too short, you'll want new ones. A good combo is Rancho RS99012 in the front, and Rancho RS99112 in the rear. If you have any $ left over, maybe Billsteins instead of Ranchos and share the part #s you go with. I want to do that!