I can't remember the cost of the adjustable lower arms (not available over here) but I wonder how it compares to the cost of having the hub rose bushes replaced, and possibly the trailing arm bushes. Yes the springs sag, but doing just the rose bushes on mine made a huge difference. The tyres were wrecked when I got it, noisy and caused vibrations. There was no tyre edge cupping for the life of the replacement tyres (even though the car still sat about half an inch low).
Priority one as I understand it is to get the car at the right height, with no rose and t/arm bush distortion.
You could address it with camber shims from Taliafero, and keep your existing lower arms, or put spacers under the rear springs. However these are both band-aid solutions if the rear bushes are shot.
Doug