Which card best for 4k gaming AND mining?

Hi people,

First post here, hello to all. I just got into the mining wave this week and having fun at it.

My rig is super simple - just a GTX 970... Getting 18mhs at the moment.

I am looking to upgrade my video card to something much better for 4k gaming. This is my primarily focus. And, secondly, I would also like a card to mine while I am not playing.

From my research, the MSI Radeon RX 480 Gaming X, 8GB is the best one, priced at AUD409. Better than the GTX 1080 priced at AUD900.

What do you guys think? Should I go with the 480 to fulfill my both requirements?

Thanks!