I have a Pentium G3258, and i can tell you that if youre gonna have one like mine, youll be depress.
I can only OC it to 4.2 ghz.
But for CS GO, you should go with a good intel cpu, and a cheap gpu.
Cs Go is like minecraft: It uses more CPU power than GPU power.
Try to start with a intel 4670k if you wnat to oc, but if you dont care about oc, go with a intel 4460 at 200$, or a 4690 at 235$.
Just keep in mind, intel is better for the cpu.
Alien_42