Side fans or aftermarket GPU cooler

Hi all,
I have a Zotac gtx670, its just at stock clock speeds and stock everything. When i play BF3 or Borderlands 2 my 670 gets up to 80 degrees celsius and the fan starts going really fast and loud. I have cleaned it out and gotten rid of any dust in there and it still got really hot. My case is a Corsair Graphite 600t special edition with just the default fans, 200mm on front and top and a 120 on the back, i have also tried turning these up to full speed and it didn't work.

The way i see it there's two things i can do to get my temps down. Firstly i could replace the crappy stock cooler with a cooler like this one: http://www.pccasegear.com/index.php?main_page=product_i...

or i could put on the other side panel that my case came with and add 4 120mm side fans blowing onto the gpu. This would cost me $50.

I would prefer the second option because it is cheaper and in the future i plan on adding another 670. If i went for the first option and added another 670 i would have to buy another aftermarket cooler for the second card.

Would the four side fans drop my temps a significant enough amount? or would i have to buy the aftermarket cooler to see any difference?

cheers for any input