Yes, the output of the radio is speaker level, rather than line level so a converter is needed. Since you will need to tap into the speaker wires, I recommend making your own harness in between the dash harness and the radio, that way its easier to splice in and also easy to remove if you ever decide to sell your jeep. Metra makes connectors for both sides: http://www.metraonline.com/part/Chrysle ... ss_71-6522 and http://www.metraonline.com/part/70-1721T. (Not sure if those are the right ones but I think they are).

You'll want to tap into the rear channel and since you mentioned two subs, you'll probably want to take both the left and right. The front channel and power/CAN circuits you'll just wire straight through connector to connector. There are plenty of holes up front to pass power and ground through and make sure you put a fuse as close to the battery as you can.