With a hub centric wheeel (and spacer) the weight of the vehicle rests on the hub itself. With a lug centric setup, you are changing this so that all the vehicle weight is now carried by the wheel studs. This setup aisnt nearly as strong and could fail with the stress. Also, several have reported a lot of vibration with the lug centric spacers.
Folks will spend tons of moeny on wheels, tires, and lifts. Why cheap out on spacers and risk damage to the rig? Go for the hub centric setup and you shouldn't have any issues.