Help me decide!

[GaiabladeX]

Hi everyone (my first thread)! In about a weeks time I will be putting together my first build for Uni. So far I decided on:

Intel Core i5-2500K 3.30GHz (Sandybridge) Socket LGA1155 Processor
Corsair Graphite 600T Midi Tower Case - Limited Edition White
Corsair XMS3 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz
OcUK H²Flo Liquid Cooler Cooler + Sharkoon Fans
Corsair Enthusiast Series TX 750W V2
Samsung Spinpoint F3 1TB
Samsung SH-S222AB/BEBE 22x DVD±RW SATA ReWriter

Now here's where I'm stuck. I HAVE to pick one or the other, otherwise my budget wouldn't fit
My choices are:

Nvidia 570 GTX or AMD Radeon 6950 2GB (Difference ~£30)
ASrock Extreme4 Gen3 Z68 or ASrock Extreme3 Gen3 Z68 (Difference ~£30)

If I were to choose the better one out of those two, I would have to pick the cheaper alternative. Better GFX or Motherboard?
Would like some opinions in what you guys would choose.

My budget is £900 and I've managed to fit all of this under it. Going to be using it for gaming, programming, 3D animation (and maybe a tiny bit of video editing )

Thank you!

 

[GaiabladeX]

Thanks Buchanan for waking me up, I'll stick with Extreme3
I will be playing BF3, Batman and some MMO's. If there isn't too much difference between the two cards, I'll just get the 6950.
I find it funny how I ended up getting both of the cheaper alternative. Haha.

Thanks again!