I'd change that CPU to either a Q6600 or a Q6700, they'll generally overclock much higher than your current choice, thus resulting in a faster CPU.
Also consider getting DDR2 instead of 3, you could get 8GB DDR2 for what you'd be paying for that DDR3, and change the motherboard to an asus maximus formula.
Samsung drives are very good, and are very fast, especially the F1 1TB ones.
For the graphics cards, 2 powercolor 4870s will be cheaper than that crossfire bundle, OC has their powercolors at £199 each.
For a PSU, I'd recommend a coolermaster realpower modular PSU, I'm pretty paranoid about Tagans as I've had a few blow up on me when stressed

, once taking out a graphics card with it.
Okay, not literally blow up, but they went out with a loud bang and some smoke to add to the effect
Coolermaster PSU
Powercolor 4870
Q6600
Geil 4GB RAM
Samsung F1 1TB
Asus Maximus Formula