Right. Two major points of contention here. That graphics card is the best single GPU available, but it is grossly overpriced. I included in simply because of the high budget and its raw performance. However, the ATI 4870, which can be purchased for £182 offers something like 10% less power but costs about 60% less too. So between, those GPU choice is entirely yours (would personally go with the 4870, maybe the 1GB edition).
Secondly, that screen is hugely expensive but very good quality. However, a 24" TN panel is just as good for gaming, something like the Samsung SM-245B PLUS 24" is perfect. Also, those Hazro's do seem to come with a lot of faults, so buy with caution.
I've gone with a P45 board, because spending £50-£100 extra for Crossfire on an X48 board seems pointless to me, plus Socket 775 is going to be superseded soon anyway.
Plus, you can obviously add keyboard/mouse/soundcard of choice to this spec later.