I have YJ rears on my rear (go figure) they fit the wheel well almost perfectly, as compared to the TJ's which are longer and either need to be cut and attached to the door, or massaging to be done to the body/flare some more.
as for the front, there are pics on here of a few YJ fronts on, they look ok too.
do a search for TJ/YJ flares you should come up with a few hits, if not I can find some pics to post up of mine later.