If we put the GPU issue aside:
For pure gaming rig, i5 4590 is way better than FX8350/FX8320 and it consumes a lot less power.
For pure budget editing rig, FX8350 or even FX8320 is way better, since you will need those extra cores or threads.
FX8350 and FX8320 are also overclock-able, which could be helpful to keep up to i5 4590 in games but with the cost of more power consumption. (edit: forget those FX9xxx, they are b*llsh*t)
i5 4590 and i5 4460 are not that difference except on benchmarks, you are free to pick i5 4460, if you like.
If we put the processor issue aside,
GTX970 and R9 390 are quite similar in performance with their own pros and cons.
GTX970 is cooler, consumes a less power, is better overclockable and similar fast to R9 390 as long as you do not exceed the 3.5GB VRAM limit. GTX970 will be sh*t slow if you go above 3.5GB.
R9 390 consumes more power, is cheaper, is not that good overclockable and has a lot more RAM.
Both GTX970 and R9 390 are moving in the same performance class. Any will serve you well.
I would not bother DX12 at the moment, by the time DX12 became mainstream, the next gen GPUs are already available.
More VRAM could be helpful for rendering/editing but do check if your rendering/editing program prefers CUDA (nVidia) or OpenCL(AMD/ATI).
Now to get the best of your money,
1. Choosing the processor:
Gaming or most games tend to rely more on the GPU than processor.
Most games tend to prefer faster cores (i5/i7/Xeon E3) over more but slower cores (FX).
Editing and rendering could gain benefits on more cores.
Which one do you do more, editing or gaming? more gaming == i5, more editing == FX8xxx
Alternative:
If I say you can get E3-1231V3, which is for normal users an i7 4790 without the iGPU and has the price of an i5 4690k, what would you say? It is the better choice but you must pay quite a lot more compared to i5 4590.
2. Choosing the GPU:
R9 390, R9 390X, Fury X, GTX970 and GTX980Ti are the best buys in my opinion. You do nothing wrong picking any of them, just adjust to your budget and match the CUDA/OpenCL to your rendering/editing software.
Yes, no GTX980 above, this card is not a good buy, it is only 5% faster than GTX970 with extra 0.5GB VRAM but costs quite a lot more.