I have installed the adjustable front axle and disc brakes without a problem. Be sure to read “PinkMG” on the proceedure.
However the ball joints are another situation. I installed the Brazillion made and the German made with the same results, a very still steering that isn’t getting any better even though I have put about 2000 miles on the car since I installed the German made ball joints. The parts place and this Form has said with wear they will become looser.
I bought trailing arms that already had German ball joints installed. It was cheaper than buying the joint and paying the local shop to press them in. At the time, I didn’t have access to a decent press.
Don’t use Brazilian ball joints.
The disc brake conversion doesn’t affect the width (track) enough to worry, maybe 1/4″ or less.
Aircooled.net has all four torsion arms w/ball joints for $180.00. I thought that was pretty reasonable. Don’t know what brand ball joints they use though. I am like you and would want German ball joints.