just my two cents but to properly water cool those parts ur gonna need at least another 25 GBP. but on parts wise.
CPU - D-Tek Fusion
GPU - EK-FC8800GTX Full Cover
RAD - PA 120.3 (preferably thermochill, dangerden and blackice are good too though)
Tubing - 1/2" or 7/16" Masktaleer
Pump - Laing DDC with top preferably petras or liang, or Liang D5
Fans - Price/Performance - Yate Loons
ur powersupply is more than enough only power that it will eat up is fans and pump maybe a total of 40w or so
another option is a 3rd party air cooler, id recommend
http://www.newegg.com/Product/Produc...82E16835109136