Hm... from my experience better go for GTX 960 he will give you better FPS even if I like R9 380, AMD higher end GPUs requires very strong CPUs to work at 100%, and due old design of DX11API is limited to 1 thread for GPU draw calls requests and AMD CPU have poor single thread performance.
For example if you Have FX 6350 @ 4,7Ghz + R9-290X in Witcher 3 1080P Ultra you get min/avg 22/34,2FPS but with GTX 970 54/58.6
This same CPU in GTA 5 R9-290X min/avg 22/26,9 FPS with GTX 970 27/32.5