Hell I'm looking for one right now!  Why by a 4x4 to upgrade?  Dana 60's front and rear, Atlas transfer case.  Makes tons of sense.  I can't for the life of me understand why anyone would by a Rubicon.......  Spend a crap load of money upfront and then still upgrade to all of the HD good stuff.  I wish they were more common and easier to find.
They should make an Unlimited with a 4 cylinder.  Then I would find it easier to chunk the engine in favor of a Hemi......  
I love my 09 Unlimited, but it has some serious issues that have to be fixed.  V-8, 44 or 60 front end without crappy assed 4:10 gears.  An Atlas transfer sure beats the shit out of the 242.....
But hey, I'm a newbie to this site, so pick on me if you will.