With a coil sprung rig you do want roll resistance, both front & rear, on & off road. A "disconnected" JK is like being in a cork bopping on water. When unlatched the TF system just reduces front roll resistance, doesn't eliminate it. It has a smaller bar inside a stiffer, outer tube. Very slick and works great. Their rear bar, just like Currie's, is a mono-rate system. No one to my knowledge makes a dual rate rear bar.
A few options, leave it stock, use Full Tractions 19mm stock style bar, or go all the way and upgrade to TF or Currie.