Fan setup for 970, 4690k build

I would like to know what kind of fan setup i need for my build. The case im using is define r5, seasonic 850w psu with hybrid mode, and a cooler master 240m, i would like to keep negative case pressure because my room is relatively dust free, i have 2 140mm fans that come with the case, 2 120mm fans on my cpu cooler and i have 2 80mm fans, my gpu is gtx 970 g1 gaming with windforce 3x cooling. I was thinking about having psu pushing air out of the case but im not sure if that will interfere with fans on my gpu, i was also thinking about having my top mounted cpu cooler pull air in and then that air to be pulled out by the fan that mounted on the back. I will be doing some overclocking. 

I have all Noctua NF-F12's, rulling in pull for my rad on top inside my case, the fan in the back is my intake, and I have a Noctua 140 as my exhaust which is in the front. I did this because, like you my room is dust free, and I have this up against a wall, so a rear exhaust would make the ambient heat rise too much. With a frontal exhaust method, it shoots the hot air out the front and away. Ive noticed lower temps over long periods of time with this method, compared to the first more orthodox method of fan placement. And my system is overclocked by ~20%. Good thing ive got static pressure out the ass.