A quick concern on cooling

I'm just finalizing a parts list for my first mining rig. I have a quick concern on cooling though!

As a background to this, I'm going NVidia, mainly because AMD cards are so few and far between, and some of the NVidia cards, I think, have potential.
Looking at this topic (https://bitcointalk.org/index.php?topic=1575547.0), I'm going with 4 x GIGABYTE 1060 3GB Windforce OC. They're cheap, looks like they can get up to about 22-23MHs on Ether, and seem to be good to get me off the ground.

Other than that, most parts are pretty standard. Going to use GIGABYTE GA-X99-UD3P as the mobo, and following some advice from a friend, I'm going with a cheap Xeon processor. (Said friend feels the reliability of them vs something like a celeron is worth the extra $50).

My concern is actually on the cooling front. I'm trying to keep the setup as neat and tidy as possible, and so I'm avoiding the whole "10 gpus hanging on a clothesline" approach. I want to put it in a proper case, and still cool it, at least for now. Other than the GPU fans, and the 3 standard case fans, my plan is to add 3 additional 120mm fans to the top of the case. I'm looking at using the Rosewill - TYRFING case, so I'm trying to figure out if the 3 additional fans will suffice for cooling. Looking at the guide here (http://www.legitreviews.com/silent-ethereum-mining-evga-geforce-gtx-1060-22-mhs_195529), it looks like 22+ MHs can be achieved at ~70C, which looks pretty stable. BUT, with 3 additional fans, will the close proximity of the cards be an issue? (i.e., not using risers) The cards would be lined up side by side like this: https://www.gigabyte.com/FileUpload/Global/Other/2/Photo/4175.png 

What do you think? Will I be ok on the cooling front?