I use 2 120mm fans,I cut a hole as you showed in the side(air in) and I placed 1 in the rear of my PCU(right behind the PCU fan)then I placed a small 80mm in the front of the case.Its a bit noisy but you can place your hand over the PCU exhaust and barely feel a difference from the inlet air.The fan on my vid card went south but I havent bothered replacing it because the side fan works so well.