There is no discernable advantage to having push/pull on a tower cooler such as a hyper212. In fact, it can often be a detriment. The push fan will push the air through that tower just fine by itself. Because of the nature of air being pushed, some of the air 'bleeds' out from the sides of the tower. This air bleed is what helps cool other motherboard components such as the VRMs which sit directly adjacent to the cpu. The draw from the pull fan eliminates this bleed, so while you may see a 1-2° cooler cpu, you are hindering any cooling breeze across the VRMs heatsink.
The stock hyper212 cm fan is quite good at what it does, and is easily equal to a Cougar Vortex in that capacity. The Cougars however make good case fans.
My recommendation is: 2x Cougars as top exhaust, set for lower rpm @900. 2x CM as front intake, set for higher rpm than exhaust, @1300rpm. 1x Cougar as rear exhaust, see same as top exhaust. Either 4th Cougar or stock hyper212 CM on the cpu cooler. Either way, with 3 exhausts and only 2 intakes, set any fan curves to have moderately lower exhaust speeds than intake speeds. This has the net effect of keeping dust down. I'd not use the side fan unless after tweaking fan settings you determine that the gpu is still too warm. Side fans usually have a detrimental affect on good case airflow, so while gpu temps are lower, everything else is higher