if you decide to go the Gen 2 *fabbed* route I can't stress enough the finding of an aftermarket set that have pressed in FIRM bushings.
The original gen 1 lateral arms bushings have no * give* to them (which is what is needed).
Some of what's out there have been fitted with *mushy* bushings, stay away from them, if you go the effort of purchasing these & then do the fab work only to find that after fitting them under your car while driving the back end wanders worse than a blind duck you won't be happy.
My solution was somewhat intense, I pushed out the poor bushings that were supplied & a close friend fabbed up a set of delrin bushings that I then pressed in. These are tighter than polyurethane, they don't give at all.
Cutting the new thread isn't rocket science, it's relatively simple, a bench vise is needed to hold the arm stationary, the M20x1.5 die, you'll need the die handle to mount the die into, spin the die onto the end of the existing thread & cut a little more than an inch of new thread. If you decide to match the new arms to the old arms length a simple 1/2"x5" bolt thru both ends eyes & lay both arms down on top of the bolts & turn the turnbuckle of the gen 2 arms so the lengths are identical & then slip down over the bolts.
Now, there is one more process you'll need to look after, the original rear arms align the toe, the old arms slide in the rear centre suspension support. Seeing as the * new* arms are fully adjustable there's no need for any *sliding at the inboard ends.
You'll want to fab up a pair of simple square *spacers* ( I used 3/16 flatbar) that are cut to fit near precisely in the rectangular recess that is part of the rear support. Drill a hole in the centre of each spacer just a hair larger than the dia of the 2 thru bolts that locate the arms there. This spacer is needed to prevent any possible *sliding* of the arms to prevent loss of the alignment setting.
The entire process isn't difficult at all.