Your footprint is gonna hugely depend on tire pressure. But at the same pressure, I would guess that the wider tire would do the trick here. Taht would be some serious math there.
As far as issues with axle breakage....think of the hieght of the tire as like a lever prying on that axle tryin to snap it. The taller the tire, the longer the lever, the more likely you are to hear ugly noises coming from under your Jeep. You are pushin yur luck with the 34" tall tire.
But it depends hugely on how you use your Jeep. It wouold probably suit you fine in the sand and even mud. But trails, tackling large boulders and logs, in low gear at slow speeds, where the tire will grab, and that lever get put to work against the Dana 30.......well....crunch, snap, bang, thudthudthud, grind (take your pick). Which ever one you pick, it won't be cheap.
I honestly believe that the magic numbers for the Cherokee are 4 and 31. Once you go over 4" of lift to get more than 31"of tire under there, the cost increases almost exponentialy. Spend the money on lockers and some armour and you'll go places the guys runnin on 35's can't.
