Gaming PC:800 (720p)

What is your budget? €800 no more.
What will be the main purpose of the computer? I want everything to play well in 720p.

Do you need a copy of Windows? No

Can you use any parts from an old computer?No

Do you need a monitor?
No Have my 720p monitor and my 720p LCD

Do you need any of these peripherals?
Would love a kick ass Keyboard / Mouse and USB remote control for XBMC

Are you willing to try overclocking?Not atm, I'd like to know what it entails.
How can you pay? Paypal

When are you purchasing? Christmas time, I think this is important, as I'd like to know of any cool stuff coming out or if the build will be cheaper by then.

Just a side note, I want a GFX that will be able to manage dual monitor between my monitor and LCD (Similar 720p resolutions) but NOT in gaming. I just want to be able to watch a movie, photoshop etc on the big screen.