actually you will get roughly the same fps out of either card. they both will hit the same speeds and will net the same in game performance.
grab the cheaper one, especially if you don't wanna think about overclocking. plenty of reviews out there that show them almost identical so i am very confident in saying this
see here for some links to some of said reviews if you wish to read for yourself. http://www.tomshardware.com/forum/id-3047729/nvidia-geforce-gtx-1000-series-megathread-faq-resources.html#17902599