Why are you using red led lights? They increase core temperatures!
Haha Jokes, Very nice mod indeed. You did a great job with side panel, kinda reminds me of Crysis for some reason.
7970 is about 4% slower than 680. But 7970 is $100 cheaper, you can picked up 7970 Ghz for $430 on newegg. But you can easily OC 7970 pass 1Ghz and save yourself some money.
7970 Sapphire V2 comes in black PCB and it's probably best...
Corsair AX series are extremely quite. I believe fan turns off when idling. But I never had a problem with any of my PSU being loud even with my older PSU.
Go with MSI Z77 GD65, That's fine, I'm currently using "unsupported" RAM in my current build and it works flawless.
I would go with Hyper blue, Vengeance RAM heat sink is fairly big and may interfere if you plan on getting a heat sink...
Off topic: Why not crossfire your 7970 and save yourself some money? Two 7970 will perform better and will be cheaper.
Ontopic: I never had issue with 310.90 and 310.70 on my 680.
I would wait for 700 series. 480 should be sufficient for another 6 months. But If change your mind, I would suggest getting 7970 instead of 670. 7970 on 12.11 driver is nearly up to pair with 680.