Mobo/Mem/Cpu/Graphics for £1100 advice greatly appreciated!

[nobby2006]

Hi, going for a system upgrade, this one just doesn't seem to cut the mustard anymore!

Current Specs

Cpu: P4 3.0ghz 1mb
GFX: Gainward 6800 Ultra
Mem: 1gig ocz 3200
Sound Card: Audigy 2

Been a good system for about 2 years now, but what can £1100 get me in line of a new supreme machine!
Already got a decent case/monitor/mouse/speakers/keyboard/hdd's and the rest.

Just need advice on mem/mobo/graphics/cpu

The machine will be used for gaming/vid editing/graphics and a wide variety of things.
Thanks for taking the time to read this and help me!

 

[nobby2006]

Wouldn't it be better getting 2 Gainward BLISS GeForce 7800 GT 512MB GDDR3 Graphics Card and running them in Sli? adds another £70 to the videocard budget, but would there be a big difference?