Optimal Fan Config?

Hi again everyone.

I am setting up my Case (NZXT Phantom 410) for my new build that will house a Asus Z77-V Pro board, Intel i7 3770k CPU and a GTX680 GPU.

For reference PSU is a Corsair 800GS 800W.

The case came with 2x120mm fans (back exhaust and front pull) and 1x140mm fan (top exhaust).

I purchased 2 additional 140mm fans (Bitfenix Specter's). I set one 140mm fan at the front and another at the top... so now I have:

-1x120mm exhaust at rear
-2x140mm exhaust at top
-1x140mm pull at front

The question is regarding the last 120mm fan.

I also have a 120mm fan on a Coolermaster Hyper 212 evo that will work as my CPU heatsink.

From a layout standpoint I originally thought I would put the extra 120mm fan at the bottom of the case pushing air up and out the top.

Now i'm debating the alternatives:

1. Set up the 120mm on the cpu heatsink to form a pull/push scenario

2. The Phantom 410 also has another internal spot just past the the 3.5" bays where a 120mm fan can be mount that I guess acts to accelerate the pulled in air from the front of the case?

3. Leave the 120mm fan at the bottom pushing up.

I might test all the scenarios but for any pros who have run similar tests would it make more sense to add it to the heatsink? or keep it on the case?

Thanks!