I think you are in the wrong section for Grand Cherokee suggestions, but the front end is basically the same as an XJ. Coils will get you about 1" less lift for a ZJ vs XJ.
OME gets good reviews from everyone that installs them, so I'm sure you'll be satisfied.
Iron Rock Offroad is a Cherokee and Grand Cherokee enthusiastic shop too. I wouldn't suggest they are on par with OME though, but still better than an entry level kit.