How does this setup look?

Cool. What elese?  

If thats your general budget I would drop down to a 3800+ and buy 2gb of ram with the saving instead of 1gb.

I think dual cores more than any thing will take advantage of 2gb.
You can easily overclock the 3800 to the higher speeds.

The graphics card is a way over priced for what it is now, you could get a 7800gt for the same price or a x850xt for £165 both of which are better cards than the 6800ultra.

Hope that helps

Just like like the other guy said, get 2 Gb of memory. It would be a lot better for gaming.

Check for GFx Cards here

Thanks peeps:
[code:1:9ec0b4d447]Asus A8N-E SKT 939 NFORCE 4 AUDIO LAN PCI-Express ATX
http://www.ebuyer.com/customer/products/index.html?acti...
£65.95

AMD Athlon 64 (ADA4200BVBOX) X2 4200+ socket 939 Dual Core 2.2ghz 512kb and 512kb Cache
http://www.ebuyer.com/customer/products/index.html?rb=1...
£252.99

Corsair (TWINX1024-3200C2PT) 1024MB (2 x 512MB Matched Pair), DDR400 / PC3200, non-ECC, Unbuffered, CL2, Lifetime Warranty, Silver Heat Spreader
http://www.ebuyer.com/customer/products/index.html?rb=1...
£73.89

MSI Nvidia GeForce 7800GT 256mb PCI-Express Dual DVI + TV Out
http://www.ebuyer.com/customer/products/index.html?acti...
£210.04
[/code:1:9ec0b4d447]

Is what I'm planning to get. I hope it will keep me going for a few years  

If it's got any compatability problems, or setup difficulties, please let me know. Thanks.