The 4670k has been replaced by the 4690k. Same price, better TIM and slightly higher frequency.
The FX-8350 is a somewhat gimped (because of the shared cache etc), old octocore with terrible single threaded performance compared to the i5. Even worse, for the vast majority of games those 4 extra cores won't be doing anything at all. I'd only recommend it for budget workstations, because then you'd actually use all 8 cores.
In short, get the i5-4690k. It's pretty much the go-to CPU for gaming right now.