Personally, I would find a used rear antiswaybar and install it. I have had the displeasure of driving my TJ when its rear antiswaybar was broken/non-functional (busted link) and the drive through my local mountains without it was surprisingly unstable. Even the three young Boy Scouts I had in the Jeep at the time noticed the additional sway and body roll and started joking about getting sick and throwing up.
The rear antiswaybar does not reduce the amount of usable
articulation for the rear axle.
One interesting fact: John Currie won the US National ARCA rock crawling championship with front and rear antiswaybars fully connected. They were Antirocks but that still illustrates the point that disconnecting both antiswaybars is not the way to better offroad performance like some think.
Personally, I run with a stock rear antiswaybar with longer links and a Currie Antirock antiswaybar up front.