I am running stock springs on my JKU. I have the teraflex leveling kit, Monroe reflex monotube shocks, airlift 1000 airbags in the rear. Without the airbags I never noticed much sag when fully loaded, but did with our 10ft pop up attached. Now with 20 psi in the bags, the jeep does not even know the camper is back there. It sits just as it did without the camper attached. The ride in my jeep is better than stock due to the shocks I am using, they really are that good. I have used many different shocks including Bilstien, rancho, pro comp and a few others and these are by far the best I have used. I have them on all my 4 wheel drive vehicles. I have about 120,000 miles on my current setup besides the airbags. I installed them this spring. I love my jeep, it is perfect for long treks ANYWHERE we want to go.
For overlanding you don't need huge lifts and massive tires. a small 2" lift, 33s, and common sense will get you anywhere you want to go.