I wouldn't upgrade your processor just yet. Are you primarily gaming, or do you do other things with this tower as well?
The advantages gained by switching from a 2600K or 2700K to a consumer 4th gen i7 are minimal. If you went the X99 route and got a 5820K that'd be another story, and there'd be rendering gains to speak of. And a small performance gain in terms of single core progression.
GPU I'd consider upgrading now, as you're working with a card that's literally living it's last days as the minimum for maxing out 1080p. Very soon you'll wish you had a single 290/780/970. I'd personally skip the processor upgrade til next generation and just get a GTX 970, or wait a small while longer and get an R9-380X when it releases