I want to use an R9 290X as my GPU. I want to go with the FX 6350 but would it create a bottleneck as compared to the more powerful i5 4670k? I'll be playing Skyrim, Planetside 2, Arma 3, and BF4.
none of the CPU's would cause a bottleneck, the best option for those games and gaming as a whole, is easily the i5 4670k, a strong CPU for gaming and performs no noticeably different to an i7.
If you overclock, go for the i5-4670k, if you don't, go for the i5-4570. If you want good performance (lower than the i5 though) at a lower price, go for the fx-6350.