Help with upgrading? (GPU vs CPU)

[Designful]

I'm not sure what to upgrade first. I want to go all out so I will not have to upgrade again for a long time as well so I'm willing to spend around $600 for a Gtx 980 or i7, but I'm also not sure if I will need to upgrade anything else before I upgrade my GPU or CPU like my PSU or Motherboard.

Specs:
i5 3470k @ 3.2 ghz
GTX 750ti Superclocked edition
Asus PB875-M motherboard
EVGA 500w psu
Kingston 8gb Ram

Extra info incase it matters:
I'm a gamer. I mostly play Arma 3 and I'm currently getting 50-70 fps constantly on as low settings as possible. I would like to be able to record and get 60 fps constantly regardless of the quality of graphics. If you think th eGPU or CPU upgrade would have a greater impact that would be much appreciated.

Thanks!

 

[flamefire999]

For gaming you don't need an i7. It's your GPU that's the problem.

I would buy a GTX 980 for the best gaming experience. You could also buy the GTX 970 is you don't want to spend a lot of money.