From what I've seen the 7970 GHz Edition is slightly better than the 770.
But if you want to go 770,
MSI GTX 770 Lightning > Zotac GTX 770 AMP! > Palit GTX 770 Jetstream > Gigabyte GTX 770 OC Windforce > EVGA GTX 770 SC
The first 3 are hard to find, while the Windforce is ~£260 and the EVGA is ~£275. The Windforce seems to perform better and quieter though.
Thank you for the suggestions did not think people would reply that fast. I have had a look at the MSI GTX 770 Lightning on ebuyer for £376.22 (pre order) so its under my price and that's always good any idea on how it would preform FPS wise?