Phantom 630 Airflow Questions

Hey guys!

So, you can check my profile for my complete build, but in a nutshell:

Phantom 630 - 200mm front intake, 200mm side intake, 2x120mm bottom intake, kraken x60 exhaust top, 140mm internal (focus on GPU's),

AND --> 140mm REAR

Now it's the rear fan I'm not sure what to do with... I originally had it set to exhaust, but then thought to try intake to try and give X60 more air. Also wanted to see if it helped cool VRM heatsinks. 

What do you guys think?