Upgrade GPU or CPU? (Both is possible)

###Build Help/Ready:

Have you read the sidebar and rules? (Please do)

Yes.

What is your intended use for this build? The more details the better.

Gaming.

If gaming, what kind of performance are you looking for? (Screen resolution, FPS, game settings)

Replace this text with your answer.

I'm mainly trying to run The Division at 60 fps, except maybe in intensive scenarios. High settings preferable, but AA/other bells and whistles off doesn't bother me.

What is your budget (ballpark is okay)?

$350

In what country are you purchasing your parts? United States

Post a draft of your potential build here (specific parts please). Consider formatting your parts list. Don't ask to be spoonfed a build (read the rules!).

Current Build: AMD FX-6300

Radeon 7870 2GB

8GB RAM (DDR3, unknown clock at the moment)

700W PSU

Other non important things

Provide any additional details you wish below. Hey everyone, I'd just like some input on this matter. I'm looking to upgrade either my CPU or GPU soon, with the hope of upgrading the other in a few months. I suppose my question is what option will give me better performance? If CPU, I'd like to stick with AMD and grab and 8000/9000 model. If GPU, probably looking at a 380. Like I mentioned above, I'd like to be able to run The Division on medium-highish settings around 60fps. Do you guys think this is possible with only one upgrade?

Thanks !