I've only installed a Rubicon Express long arm kit in a 1998 cherokee. Took quite a bit of work. more than I expected. all said and done, 2 weeks start to finish. Even after install was complete adjusting control arms and track bars to get a straight tracking XJ took several more weeks to fine tune.
I have a long travel kit in my JK and it was only a 4 hour install with basic hand tools and jacks. No cutting or welding required. Very happy with it, OME LT kit from Northridge.