Best may be with top vents blocks except for ones directly over GPU fans as intakes with fans moving cool intake air to GPU fans.
Like Ciarlatano said, experiment and monitor compoennt temps or even better monitor airflow temp going to components and pick the best combination and fan speed curves.
Phanteks Owners Club Ways to Better Cooling
i7 980 @ 3.55GHz =PH-TC14PE w/2x TY-143 fans =Crucial Ballistix 3x4GB =GA-X58A-UD5 =ASUS GTX580 DirectCU II =Enermax Modu84+ =Define R2 w/3x TY-140 case intake fans; all PWM controlled by CPU fan socketPhanteks Enthoo Primo MoBo Rampage III Extreme CPUi7 980X
@ 4.0GHz =R1 Ultimate
w/2x TY-143 fans =Dominator GT 6x2GB
=Rampage III Extreme
=ASUS GTX580 DirectCU II
=Enthoo Primo w/ custom castor base