Reply to "Adjustable A-Arm Fabrication"

Because the two pivoting ends in the illustrated a-arm seem to be running at quite different angles, you will need a heim-joint in at least one of the pivots. Johnny-joints are simply encapsulated urethane (or other material) bushings with very limited capability for misalignment. At those points, a pair of adjusters' only advantage might be for setting toe- which on the Pantera suspension is done with very similar parts and shims already on the lower a-arms. And since a bent tube (between the pivots) has little stiffness, I would triangulate the 'brace' up to the ball-joint end with a pair of gussets.
As for fabricating adjustable upper a-arms from scratch, if I was to do such a thing, I would use stock-type chassis pivot ends (with urethane bushings) and make the connection to the upright the multi-angle/pivoting/adjustable part. Advantages are, you have one part to adjust, and if a heim joint to added there in the fashion McLaren did on their racers, camber adjustment can be done without disassembling anything at all; lock-nuts hold the adjustment.
By using a cheap & readily available tapered stud in the stock upright to adapt a heim, no changes there are needed either, and the same suppliers have heim-joint seals reasonably priced. Varying the height of the heim to the upright on a stud with shims can allow changes to the instant-center in the rear, which will yield changes in handling- maybe good, maybe not. Each car is a little different.