Unless you're a massive audiophile I'd not both with the soundcard, these days onboard sound is very good and if you're a massive audiophile then you'd want a batter sound card anyway.
Monitor, nice although personally I'd go with a cheaper on and get a display port adaptor
http://www.scan.co.uk/products/23-lg...0cd-m-50000001 or http://www.scan.co.uk/products/23-lg...0cd-m-50000001
I still say the graphics card is massive overkill that you're never going to need or use, unless you start playing games on it.
Sticking with the same brand of card a 6770 http://www.overclockers.co.uk/showpr...56&subcat=1982
To just output a desktop and video feed (ie bluray/dvd watching doesn't need much power at all, even with 3 monitors.
It might be worth looking at the corsair H100 all-in-one cooler http://www.scan.co.uk/products/corsa...6-2011-am2-am3