I just bought a NZXT Phantom 820 case. I have a Corsair H100 cooler. Will it be okay to keep the 200mm fan on the top and fit 2x 120mm Cooler Master Jetflo for push ? Will it do sufficient cooling or do I need to use 120mm for pull also ?
Absolutely, the whole reason cases developed the top air vents was to dump hot air from the processor OUT of the case rather than ON to the graphics card and other components. I think you're sticking true to the design philosophy and will do just fine