Just an FYI, if you've got a lot of MJ specific questions, check out
www.comancheclub.com It's a great site with a lot of great info and great people. Not as many hose-heads as there are at this place.
As far as the SOA goes, there is more that goes into the equation than just the axle tube diameter. What spring perches are you using? Was your MJ 4wd from the factory, or did you convert a 2wd to 4wd? The 4wd had a taller stock height to begin with, so it will end up sitting higher than the 2wd rear spring will. If you want to lower the rear at all, swap in some 2wd springs. When I owned my MJ, I also did SOA with the 8.25. Mine was 4wd from the factory, and I ended up with around 6-7" of lift. Some of that was also due to the spring perches I purchased, which sat taller off of the axle than the stock XJ type perches do. All of this adds up- In height and in cost. Your lift height will be: axle tube diameter + spring pack thickness + spring perch height(most people forget this part).
In the rear it's no big deal, but the front will give you problems because so much more is affected by an inch or two. 7" is a lot to stuff under the front of a Jeep, not that it can't be done. I ran Rubicon Express drop brackets, tall springs and a spring spacer, and a TNT track bar, and a drop pitman arm. I sold it before I did anything else with the steering, but it wasn't all that bad. I ran 33's, but I could've fit 35's if I wanted to trim. You'll also need to be conscious of your brake situation. Read around for the WJ master and booster swap, it's well worth the time.
Good luck with the build, but the guys at ComancheClub will have a lot more info on the SOA.