at £950 it suggests 280X crossfire. 
edit: I'm not too fond of these generators. If you dont know what parts you should buy, then you are not up to the task anyway (imo). I usually read reviews and compare prices and features for most parts myself. All that is part of the fun of putting together your own machine.
"Enlightenment is man's emergence from his self-imposed nonage. Nonage is the inability to use one's own understanding without another's guidance. This nonage is self-imposed if its cause lies not in lack of understanding but in indecision and lack of courage to use one's own mind without another's guidance. Dare to know! (Sapere aude.) "Have the courage to use your own understanding," is therefore the motto of the enlightenment."
