Ok, the rear is good for shit tons of lift. There's tons of slip in it. Because it's so long U joint angles don't get too bad. The gas tank crossmember will limit down travel before the U joint binds.
The front little drive shafts are puny as all hell. An aftermarket drive shaft is gonna cost ya out the butt.
The diff stays in the crossmember and doesnt move, like if you were lifting a solid axle truck or TTB.
I'd think you'd be fine to run the stock drive shaft and if it blows up just pull one from a junk yard. 10-20 bucks.
Really thought, how often are you in 4 wheel drive to wear on the drive shaft?