I was (will) going to upgrade to a 970/980 this year (from a 560 Ti, hehehe) so on that side I have no worry but I am still running an i5 2500k, I could OC it but I don't know if I should just upgrade it as well, do you think I will be at a big disadvantage when running the game? Given that I don't want to run it on medium nor low... I just don't know if the game will heavily benefit from the CPU.
Sandy Bridge with a single GPU, I think you're fine. The memory system on Sandy Bridge turned out so well that the server model of these CPUs is still current. What you don't get is PCI-e 3.0, and you would want that only for high-end SLI.


