Assuming dual shock you are referring to reservoirs; they are nice, but aren't necessary if you aren't off roading your Jeep with quite a bit of speed.
The whole point of a reservoir shock is to provide better cooling during heavy use. For a large majority of people, a standard shock will serve just fine.
If your speaking of monotube vs twin tube, monotube is going to win. They are more performance oriented and have less shock fade by design. I run Bilstein 5100 and they have been awesome. I hear fox and rancho are great also . Previously had procomp which sucked bad. You can do a Google search for more detailed pros and cons.