£720 gaming pc

Hi guys i have posted before about a £500 gaming pc which didn't enitely go to plan (it didn't happen), and now i have £720 to spend on a gaming pc. I do not mind if i go slightly over budget if the extra is worth it and i would like to also keep it under if possible as i could use some of the left over budget for windows 7 64bit.

I have a 1440x900 monitor and will not be upgrading it anytime soon. I have a mouse (mx518) and a keyboard (g15) already so i dont need them either.

I will be using this pc mainly for gaming and for a bit of light video editing too.

The sort of games i would like to play are bad company 2, gta IV and team fortress 2.

These are the parts i have chosen so far, i would appreciate your critisism on the build and tell me what i could tweak so i get more for the cash i have.

http://www.ebuyer.com/product/138586
http://www.ebuyer.com/product/127584
http://www.ebuyer.com/product/124228
http://www.ebuyer.com/product/166995
http://www.ebuyer.com/product/206153
http://www.ebuyer.com/product/176026
http://www.ebuyer.com/product/191826
http://www.ebuyer.com/product/190673
http://www.scan.co.uk/Products/1GB-XFX-HD-5850-Black-PC...

TOTAL- £718.22

If the build is not entirely what you would have in mind for a gaming pc feel free to create a totally new build design, all i want is solid gaming performance in the games mentioned at the lowest price.

NOTE: the operating system will cost me £45 (its windows 7 professional 64bit student edition), it DOES NOT have to be incuded in my budget price as i can purchase it later on down the line, but if you can fit it into my budget then great!

DON'T FORGET IM FROM THE UK!

Again thanks for your help in advance as i know you guys take up your own time to help others.