Thanks AV8, I usually self build but fancied letting someone else do the work for a change, however after pricing all that up on Scan to find it can be had for around £1100 I may still go down that route. The case at £170 odd is probably a bit of an extravagance but for liquid cooling and quietness it may be worthwhile.
As for what it will be used for, I'm on the beta for a forthcoming DX10 update to a popular title which will make use of the 4 cores and am looking at a Vista platform with about 3 years of future proofing built in hence the high end specs just now.
I'm currently running XP with a 3Gb switch to make the most of the available memory, 64 bit Vista can make use of up to 8Gb using Intel 955X on Socket 775.
Cheers,
5711