Sorry, you can't pay me to do that in any vehicle! Yeah, i may go up it...if i had enough underwear stashed away in the car......but going down, i would kill before doing that!
However, IF i am force to go down, then i would pick Rubicon LONG-wheelbase due to the steepness (LWB over SWB) and 4:1 Transfer case. The 4:1 TC will be the key here...it is almost a "must-have" in these stuff. Going up, i would take the 2010 Trail (with CRAWL) or Rubicon LWB. For me, going up, i would lock every locker(s) i have...and the general rule for going down is: whatever you use to go up is what you use going down.