stick with the poly bushes,there far better than the rubber ones on ride and cornering,buy a pinch bar and go under,get someone to turn the steering,look for any play you will see it a mile off,you have to check everythng,uv joints,play on the steering joints movement or play in the track rod ends and pitman arm,the whole lot,check uper and lower control arms,there may need torque on them,do this with the car on the ground or up on flat ramps,as long as there is weight o nthe wheels,check the back spring bolts and springs,one of ours was slack.,front wheel bearing could have wear and upper and lower balls joints,check them.
get shot of the kids,the wife,put the phone off the hook and take your time,get a friend ot give you a hand check the steering,remember safety when you are under a car like a cherokee.
let us know how you get on