GTX 680 4gb2560x1440 vs 1080p

Hi everyone,

So am I am looking to get a new PC and am not sure what monitor/video card to get. So I am getting a water cooled PC, and was wondering if 2560x1440 resolution is a massive improvement over 1080p. I will have to get all my parts from this website though: www.pccasegear.com
I was looking for the 1440p monitor to be a Yamakasi Catleap. If I get this, my graphics card will be a 2 x 2gb GTX 670. However, if I get an Asus VX238h, I can get 2 x 4gb gtx 680. Or I can buy a bigger SSD as my one is only 120gbs.

Thanks