Cabinet Cooling

I have all of my components in a homemade media cabinet with no doors.  After adding amplifiers, I noticed a heat issue after prolonged use.  Since the front of the cabinet is open, if I add some fans in the rear of the cabinet to pull the hot air out, will that be sufficient, or would it be better to pull cool air in from the rear?  Pulling the air in has me concerned about dust buildup on the electronics.