Silverado Cold Air Intake?

I have a 1997 C/K1500 Silverado Z71 im rebuilding into a serious off road bush buggy (new 5.7 V8, new transmission, 3" lift kit and tires, ect). Im trying to decide on a cold air intake (K&N, Volant, Airraid) and want to find the one that will give me the best perfomance and power while giving me a boost in the fuel economy department. Now let me say ive heard there is debate on whether a CAI and exhaust increaee fuel economy but if they do, which one will give me the most "bang for my buck"?