Long arm means you can throw your tires over some huge boulders (like 3-5 feet tall if you got huge tires) and not worry too much about scraping and moving your body on top of the boulder and such. The L/A from fabtech replaces the geometry for the Jeep by using new control arms and mounting a new frame for the c/arms closer to the treanny skid plate. Alot of articulation. This is made for the serious rock crawlers to do the most extreme stuff. If you got stock 35 and 30 it is almost not worth the money unless you plan on upgrading to a dana 44, ford 9" 8.8" , dana 60 or something like that. youd break your axles apart. Unless your doing it for show.
I would just stick with a mild 2" lift, with some aftermarket 4wd.com c/arms for your stock jeep cause really the most you can go as far as tires are concerned are 31's to be safely locked. Maybe 32's.