You can certainly run the game with that. I don't know how well, Beta is meant to be a lot more optimised (coming out tomorrow), but I'd guess maybe on the standard default setting, so not low or high.
A GPU upgrade will help a lot more than RAM upgrade. A 960 is better obviously, looking at some things online it looks like how much better depends on the game. 960 is far better at games which use a lot of tessellation for example, I think. But I am not totally sure it is worth it. Unless you can get it very cheap, or perhaps stretch to a slightly higher end card you might do better to wait until the next gen GPU stuff comes out in the summer, they are likely to offer a significant jump in performance. That obviously depends on your current needs and wants.
A dev could obviously give a better idea on the hardware front. We might be able to say more on the performance front once the Beta is out and we have a slightly better idea of performance. At one point one of the Devs mentioned they may base a lot of their optimisations around the 960 as it is a common mainstream card so that would be in favour of the 960.
