It makes no sense to try to figure out how much lift you want until you're decided what size tires you want to run on it, because generally we try to intall only enough lift to insure that the tires clear the fenders and other parts of the vehicle when used in an off-road situation.

So, my advice would be to consider what type of off-roading you're going to be doing, in what locales, and what size tire will be necessary to clear the obstacles in those situations most of the time. Based on that analysis, decide what tire size and configuration you want.

Then, decide how much lit and what type lift you want to install in order to clear that tire.

By the way, on unibody Jeeps or other vehicles, you won't be able to install a body lift, so a suspension lift is your only option.

Also, after you figure out what the new tire size will be, then you need to compute what your new differential gear ratios will havre to be. As a starting point, select a gear ratio that will give you the same equivalent gearing as present, plus about 10 to 15 perent more (lower) ratio to be able to turn those big tires. If the tires exceed 33", you should also consider brake upgrades.