Go with the 1200. Make sure you get a b350 series motherboard to be able to overclock though. But the GTX 960 is basically equivalent to a GTX 1050 to GTX 1050ti. Essentially the card will likely hold back any potential performance benefit of one or the other. Once the 1200 is overclocked, it should be close.
https://m.youtube.com/watch?v=zUeUzAtzUZA
This should give you an idea. The guy ran some tests even with a GTX 1070 with each CPU, and when running high details, once the ryzen 1200 was overclocked, the 2 processors seemed to read blows.
I didn't watch the whole video, but the chart I saw during the video suggested that. But have a look and see what you think.