The XJ rear springs are an exact replacement for the 2 and 4 door sedans and 4 door wagons. Not the Kammbak or SX/4s, unfortunately... I've done a pretty fair amount of research into spring dimensions to find that out.
I'm going to be buying my 9th Eagle befroe the end of the year. I'll be using Old Man Emu XJ rears for 2" over stock in the rear from Rocky Road Outfitters (rocky-road.com) with new fronts from NAPA #277-3188 that are from a "Commercial Chassis" AMC Matador along with a 1" spacer to replace the stock spring seat on top of the spring from Autozone. I should net just over 2" from stock until the springs settle, then it should be pretty much 2" of lift.
I'm not sure what I'll be doing about shocks yet. I'm going to use an XJ D44 rear with 3.54s and replace the vacuum disconnect front at the same time with one that has 3.54s as well. I'm going to use a NP208 from an early 80's fullsize Jeep for low range, simplicity, bolt-in, more rear driveline length, and to eliminate the problematic viscous coupling.
My goal is to have a capable wagon with more longevity with the drivetrain than stock and to comfortably clear 31s and be able to pull them down the road without a great deal of strain. I live in BFE right now and I'll need it to be able to go more than 200 miles 1 way without wearing me out.