Well, it's more of a caster adjustment than just using someones lengths. That will get you started, but you really need to check the caster about 7.5*, that's the point of having adj. uppper arms anyway.
It depends on your lift height...there is no set length on control arms no matter what you have done. I would rough estimate the lowers and get fixed ones, and then get adjustable uppers to set caster, and pinion angle. I'm sure if you call RE they would help you out.
gearwine... you are right of course... I guess what I wanted to know was if using the drop brackets would require a set amount of added length to the arm length I would normally have used with the arms in the stock locations.
I will call RE tmrw and see what they have to say...