Given
this chart, I'd be tempted to go for the 7970 Ghz ed. Also, while speculation, I'm wondering if PC games will start to cater to AMD's GPUs in the coming years now that all consoles will be using AMD GPUs. Nvidia said that this won't happen and that they'll continue to make drivers and cards, but I've seen what developers can do when they are given money by AMD or Nvidia to optimize specifically for one of the card makers...
The 770 is a 680 with better Boost technology, plus slightly faster memory.
In reality, each should be fairly similar in terms of performance, so you really won't lose out in either case. Each you should be able to overclock yourself and have decent results, so I wouldn't let that be the deciding factor.
On an unrelated note, I'd probably go for a 120GB SSD if you could. 64GB is doable, but you've got to pay much more attention to what you're doing, where you're installing things, where you're unzipping files, etc. I've got a 60GB SSD in one of my laptops and it is a pain to remember to do those type of things, while the 120GB SSD in my desktop I'm no longer concerned by anymore.
Also your PSU is overkill for your setup. Given this awesome
PSU calculator, even with a 4GHZ overclock on your CPU, you'll be pulling down around 400W at max power draw. You'd be fine with a 600W PSU if you wanted, and even that would provide extra power should you require. If you're going to be using Crossfire or SLI at some point, then I would say that the 800W PSU might work out a little better.
Looks like it's going to be a helluva beast by the time it's running! Congrats
