I've had an i7 for a couple of years and can throw pretty much anything at it. Cranks right along...love it.
Highly recommend nvidia on the gpu. My 5x series is still doing great, and a 6 should last you years. Unless something hugely hardware dependant comes along soon, we've almost reached a golden age where any recent video card looks/runs things reasonably.
Memory, I'd recommend 12 gig, minimum. 8 is plenty for me now, but assuming you're going to have this system for a few years, it never hurts to plan ahead.