I think it will run things fine on mostly a mix of Ultra/high stuff at 1080p. The 7870 XT is a big step up from the Ghz Edition though, if you can find one at a similar price.
Where are you buying the RAM from? I'm sure you could better 1600 Mhz RAM for at most a couple bucks more. This is a minor point though, and a lot of people don't buy into RAM speeds making a jot of difference. My opinion is if you can have it for $2 more, why not.