Help with a new PC

[Phyziology]

I'm planning on getting some new parts for the holidays. Ive recently gotten some new parts and am stuck on what GPU to buy. My budget right now is around $350 USD, give or take a few bucks, but am looking for a powerful card to play games at 2560 x 1440 resolution. Also 4K is getting more and more realistic for me. My specs right now are

 

AMD FX-9590

ASUS Crosshair V Formula Z

16GB Corsair Vengance DDR3 1600

PowerColor HD 7870

Hitachi 1TB HDD

EVGA SuperNova G1 1000 Watt PSU

Fractal Design Define R4 - doesnt really matter haha

 

Ive been looking at the MSI r9 290x Lightning, Gigabyte Windforce GTX 970, An older GTX 780, And really good deals on 780 Ti's, but have had no luck with that one. I just need to know what card will perform the best while playing demanding games like Far Cry 4, Battle Field 4, and AC Unity at 1440p and also something that I can put in SLI / Crossfire in the future for 4K. Thanks for the help

 

[Enderman]

970

[ChatDaw]

290X would be a good option in my opinion.

[SteveGrabowski]

I'd go 290x if you're sure you're going to CF for 4k. Well, if you can have a decent amount of space between the cards to allow good heat dissipation.

[viperatedrko]

I think the 290X would go well

[BulkFish]

I like the gigabyte 970 personally, but that's just me. The 290x would also be an excellent choice.

Don't forget to add Freesync/G-sync into you decision.