BillK, I reread your original post. I must have misread it, sorry.
While I agree with you that the Jeep Cherokee is a complete POS, it is a good off-roader bone stock. It has good ground clearance, solid axles which give good axle travel and stability, and has a true 4 wheel drive transfer case. It doesn't have a frame; it is a unibody construction, thus the flex in the body. I had one myself and experienced the groaning, creaking and eventual breaking of things. That's why I bought the Land Rover Discovery.
Now to the subject of modifying a X5 for off-roading, its not really feasible. Having independent suspension makes any kind of lift extremely difficult. With a solid axle truck, its as simple as swapping the springs and shocks and attending to any driveline angle issues because of the lift. On a independent suspension truck, lifting it is much more complex because of the camber effects of the lift. Also, the breakage factor goes way up because of the increased angles on the cvs. There was a company that did a suspension lift on a LR freelander. On the first off-road trip, it blew a cv joint and took the transmission with it. Independent suspension trucks are best left alone. If a off-roader is desired the best solution is to start with a solid axle truck and go from there.
Going back to LR, one of the best bone stock off-roaders is the 2004 Discovery Series 2. It has the 4.6 litre engine and CDL standard. It is a great compromise on-road / off-road truck.