I have not driven a JK with a spacer lift, but I have driven ZJ's, Tj's and a WJ with them. If you get a decent shock they are typically the most oem like. Not usually a lot of difference between manufacturers. Some chassis require bumpstop and brake hose mods and not all kit account for that.
Shaffers OffRoad Rocks!
Other Companies that have treated me right!
and KC Hilites