The advice these guys have given is good stuff. The only thing that I would add is the link length...... The shorter the bottom link, the higher percentage the top length should be. So let's say you end up where you only comfortably fit a 20" bottom link, then you will want closer to 20" on the top. That would reduce some of the bind during roll that would be created with a much shorter link. To give a point of reference on that length, it is 19" (if my memory is correct) on 3rd and 4th gen F-bodies. That length seems to work fine as roll steer goes, but longer would theoretically be better.
When working on "bagged" suspension that has a fair amount of travel and using 22" lower links on a shorter wheelbase than yours, the bind from using shorter 18" angled upper links would split poly bushings and kill u-joints. Replacing the urethane with rod ends made the ride quite harsh. Simply moving the upper mounts and going with 22" uppers brought this back where it should be.
Usually these projects "evolve" quite a bit during construction...... So the choice of these upper link mounting styles you choose, and how much pinion angle change you want, will dictate the length ratio...... Of course that is only one man's opinion.
Beautiful project BTW
