I have not seen a street kit for a comanche. But you can build one pretty easily:
1) I will be using a set of front cherokee coils with 1.3 turns cut off. This should yield around a 1.5-2" drop. Cut less or more to vary the drop amount. I have Monroa sensatrac shocks made for a cherokee.
2) WJ lower control arms. Should take some of the flex out of the stock design so that you can corner a bit better. Also have a bend in them to clearance tires so you could inboard the fronts some if you want to.
3) ZJ swaybar, or a thick cherokee one if you can find it, I think it is either 28 or 30mm for the good one, then use urethane mounts and bushings.
4) Leaves. This is the hard part. I started with a set of Cherokee shackles in order to drop it some right when I got the truck. Now I need to either take a leaf out, or put some drop blocks in. You could have a new pack made with less lift and more stiffness too.
5) ladder bar, since you are not worried about travel or flex, you can run quite a few different setups. Also, you can try adding a rear swaybar.
I am hoping to do this to my MJ in the couple of months I have between training. I saw pictures of the race truck and of the world speed record truck and other than a traction bar and a bit of a drop I never saw anything special in the design. I also have a WJ brake setup for when I finally find a set of Moabs. And I also have a Trans AM "Z" steering box for when I convert to power steering, it is a turn and a half box.
I have a design for a bed cover that will sit flush in between the bed rails, but I have yet to build it. That should help out with looks and milage, as well as giving me a lockable storage place, not in the cab.