Nah....you don't have to run rear shocks...if you want to die.

Not running rear shocks is a bad idea. I've seen bad rolls off of hard obstacles and a bad roll on a logging road squarely due to the drivers thinking they can get away without rear shocks.
The truck won't handle or react properly on the street either, and your rear end will bounce all over the place, and and and....and axle wrap will be horrible (assuming you don't have a anti-wrap solution already).
It's not rocket science to go down to the local parts store and look through their shock cateloges to find something that will fit properly.