Oh man, look at that.
You are paying 50 quids more for a 25/6o increase in performance. It's not worth it man. You can easily overclock the non-extreme edition to exeed that of the extreme one
Even the 7900 GTX might not worth the money. If i were you, i will look for a lesser card ( 7800 GTX or 7800 GT or 7600 GT ) then upgrada later when the 7200 series come out.
Dont know about you. But if budget is not a problem for you then just go for it. Look at ebuyer.co.uk if you want to buy stuffs a bit cheaper.
DFI Lan party UT NF4 Ultra
AMD Opteron 146 2.0 Mhz @ 2.8 GHz
OCZ Gold Edition 2x512 MB DDR 500 timing 2.5-3-3-8 @ DDR 560
XFX GeForce 7600 GT 256 Mb GDDR3
Antec Lanboy Mini Tower Case
Antec True Control 550W ATX2.0 PSU
Maxtor 300 GB 7200 RMP SATA 16Mb Cache
17\'\' TFT Screen 12 ms