Not totally sure they make a leveling kit for that year. I know they have them for the TTB fronts, but not coils and A-arms.
I would start at your shocks. I had the stock ones and they could not handle the extra weight of oversized tires. Put on some KYB's and problem solved. However, that will fix the up and down impacts....
To really make a Ranger ride like butter you HAVE to remove a sway bar link. I bet you think I'm crazy, but seriously... you cant knock it untill you try it. It was the best thing I have EVER done to my truck. With the sway bar disconnected you can charge over potholes and not feel a thing. Its epic. And honestly the increase in body roll is almost nill with new shocks.
FORD: PRACTICING SUPERIORITY THROUGH EQUALIZED MEDIOCRITY SINCE 1906
Daily: 2000 Ranger XLT 3.slow 5spd 2wd. Fabtech spindles, Belltech shackles, Expo springs, 265/75 R16 Duratrac's
Track *****: 1986 VW Golf. 1.8 8v on a webber at 8k rpm, scale weight 1670 lbs.