Here is what i think a decent AMD based build should be like.
Going to base it on Windows 7/8
AMD Fx 8350 4GHz - £151.55
Gigabyte GA-990FXA-UD5 AMD Socket AM3+ - £140.80
Corsair Dominator 32GB 1600Mhz Quad Channel - £274.82
XFX AMD Radeon HD 7970 3GB x2 - £639.16
Samsung 840 Pro 256GB - £189.00
Corsair AX860W PSU 80plus Platinum - £144.72
Fractal Design Define XL R2 Gaming Black - £108.85
Be Quiet BK017 - £58.78
Seagate 7200.14RPM 2TB SATA3 HDD - £63.01
Grand Total -£1770.69
Why 32gbs of ram for gameing?
Anless you what to use a 20gb ram disk :) http://www.amd.com/us/products/desktop/radeon-memory/Pages/ramdisk-overview.aspx
This would be amazing as well as look amazing. http://uk.pcpartpicker.com/user/Killerfrenzy96/saved/1Why
take a diffrent mobo, especialy if you plan to go into overclocking.
The Gigabyte GA-990FXA-ud3 is not a great board for overclocking. i would say for the money trow in a Asus Sabertooth 990FX R2.0 or GEN 3
Why are you getting such a big case for an ATX motherboard and a single GPU? I would personally go with the Fractal Design Define R4
+1 for sabertooth, although you will have no problem getting a decent overclock on the gigabyte board. 8350 is extremely easy to overclock.
What is your budget? If you don't have too small of a budget you can throw a Corsair H110 or a Kraken X40 in there if you stay with the XL case, if you do get the R4, the best Radiator that would fit would be the Corsair H100i. I also wouldn't reccomend any of Fractal's cases if you want to make your own custom loop, I have the R4, and it is quite tight on space.