Setting up a 4x4 to handle well with custom suspension can be tricky at best. Sway bars, coil springs, shocks, and suspension geometry all come into play when deciding how a vehicle is going to handle. And vehicle manufacturers spend millions of dollars making sure a vehicle's suspension works as well as it can … in stock configuration. But, everything can and does move differently once we start lifting them up, adding stiffer springs, and changing the valving in the shocks.
Most 4x4s (at least ones that would be considered good build platforms) are constructed with a compromise of on-road handling and off-road capability. While the vehicle should not sway too much at higher speeds, you want a certain amount of flex in the suspension beyond what a "normal" passenger vehicle would offer.
When modifying suspensions in the aftermarket world, it's generally a good plan to mimic the original suspension in handling characteristics to give you the best blend of daily driveability mixed with off-road performance. But that is easier said than done.
All too often a suspension modification to improve one facet of suspension movement can worsen another. A softer spring may give a smoother ride, but it also allows your suspension to bottom out with less force than it would need with a stiffer spring. Removing a sway bar may give better axle articulation, but it also allows for a lot of body roll when cornering at higher speeds (both in the dirt and off road).
On our own Cherokee project, we've tried a number of spring, shock, and sway bar combinations—all close to each other, but with slight variations that have had dramatic effects on performance. We think we've finally found our correct combination using Old Man Emu (OME) coils, Bilstein 5160 shocks, and a Currie sway bar. But, trial and error can cost a lot of money that would otherwise be saved if you knew the right combo to begin with. Look at others' vehicles and start asking questions. If there is a known formula for your vehicle, it'd benefit to use that as a starting point (and hopefully ending point if you're satisfied).
Something else to remember is that not everyone wants the same thing. While a go-fast guy may want a stiffer, tighter suspension with crisper handling, a trail-riding guy may want a softer, gushier suspension that can absorb contact with large boulders but is maybe a little too loose for safely traveling at higher speeds.
Whatever your choice, it pays to have experience (yours or someone else's) when setting up a suspension.