Sounds like you're asking whether to select a Solid Axle vs Independent Suspension?
Solid Axle only does well for Rock Climbing when driving very slow and the diffs are locked.
Independent Suspension works better in every other situation when cornering at speed, whether flat surface to bumpy terrain with jumps, etc.
Be sure to select a kit with sealed gear diffs, many low end kits will not have sealed diffs and they will drive like crap... you will get what you pay for, remember this.