I have have the same configuration and i was stuck with the same problem of choosing that GPU to purchase.
AMD Fx 8350 with Gtx 760 is a good option , but you will unnecessarily draw too much of power also the cost will be higher,
A slightly lower performance will b with GTX 660 Alone. But will will draw low power and will remain much cool.
Also to be noted in both cases its Either Gtx 660 or AMD Fx 8350 with will take the load and not the Gtx 760 as it will comparatively low in performance then the other two cards.