£211 from Scan - XFX 7950GT XXX version.
£170 from Scan - MSI 7900GTO
Toms doesnt have the GTO or the XXX version with a 610Mhz GPU speed. From the charts the 7900GTX is better than the standard 7950GT, neither compensates for the Different clock speeds.
AFAIK the GTO is the GTX with cheaper and slower memory modules and a slower bus. This means less OC capability. Anyway, i think the GTO is a great card whose performance is superior to the 7950GT.