Unfortunately, I can't order from newegg as I live in Denmark (and as far as I can see, they don't offer international shipping).
The MSI Lightning is also rather pricy (I will have to put out about $700 for it). I was looking at the Sapphire Radeon HD 7970 and Gigabyte's GV N670OC-2GD. Why should I go for AMD when running in a resolution of 2560x1440?
Since the difference is slightly noticeable, go with the cheaper.
The GTX 670 Windforce 3X has the best cooler out there, and some members reported overclocking up to 1225 MHz. There's nothing wrong about it.
So with the 7970 being close to $50 more expensive, the GTX 670 should the my choice? I'm given to understand that it uses less power as well, which is always a plus. If we were to guess how long it would last, what would you say (talking about playing games at close to max. settings at 1440p with a relatively playable framerate)? With the next console generation (hopefully) coming out soon, we should be seeing more demanding games within the next few years.
Next few? No you can't predict that at high settings,that's why i told you you'd need a lot of graphics horse at this resolution. One game may turn over the whole matter. The new Max Payne 3 Requires 2038 MB of VRAM if you'll enable 8x MSAA @ 1080P, so it will require more if you play it at 1440P, that's where the HD 7970 shines with the extra VRAM.
So to sum up, I'd recommend HD 7970, cause it may be useful later. And regarding the power consumption, the difference is not huge between GTX 670 and HD 7970 so I guess it wouldn't make a difference too u.