Define r5 fan orientation

I know, I know I am posting on here again hoping that the brilliant community will come to my rescue again LOL.

I have my shiny new define r5 windowed edition
and just was wondering what is the best fan orientation for cooling and quiet operation.

I was going to leave the stock 140mm in the back and mount my NZXT kraken x61 in the front using the 2 140mm fans that come with it and move the 140mm fan that comes in the front to the bottom to push cool air into the 2 fans on my EVGA GTX 980 ti superclocked + acx 2.0+ GPU to cool that.

Would this give good cooling bearing in mind I want to keep the mod vents in the top in (if possible) for the silence.

Many thanks,

Yes and no.
It will be good solution, but R5 is either cool or quiet.
Getting R5 for the silence means you loose a couple of degrees in thermals.
Getting the case for cooling means you need to remove the moduvents and loose the silence aspect. And even then, the limited front intake and unfiltered roof panels makes it a bad choice to go for good cooling performance.
The configuration you have chosen is kind of the best possible solution without removing the moduvents.

In general it is better to have more intake than outtake, when I built a pc for a friend with this case I went for 2 intake in the front and 1 outtake in the back.
This pc was built with an air cooler, but I suppose you can replace the 2 front fans with a radiator for the Kraken.
Concerning the extra fan you'd have to move, I'd try to test with it both in the bottom and in the top. My experience with fans in the bottom of the case is that it can cause a lot of dust buildup if your floor isnt always the cleanest or you have carpet.
Also the bottom fan could interfere with the airflow from the front frans, resulting in less air reaching your GPU.
Lastly you could consider just mounting the one extra fan onto the rad for better cpu cooling performance, not sure how it works out in this case however.
It's always good to try out some configurations.