All I can say is go to Gojeeps sight and follow it to the letter! He has the perfect write up.
I have 3 and 3/4 inch lift and the bags I got off Gildo (thanks!!!) were just the right length with the top bracket flipped, as in gojeeps write up here:
http://www.go.jeep-xj.info/HowtoAirbagSuspension.htm
The only problem I had was that to mount the top bracket straight above the bottom bracket it was intefered with by the OE bumpstop. But the new bumpstops I installed (also sourced from this site) were not a problem.
So far I have set them up just to manual air up. Later I will add them to the solenoids (covered earlier) in the rear, once I have finished rear cargo storage install. Hopefully this week sometime.
After that:
Auxillary tank
Winch
Intercooler
Hoodvents
rearwheel carrier (twin carrier)
roofrack
and then:
Bigger lift
fender cutouts
bigger wheels/tires
lockers
rock crawling gears.
Oh I forgot. I have to connect my twine heat exchanger....might do that next.