you dont want to get into shipping things overseas, you have to pay US tax and UK tax and any other charges Customs can think of + postage is enormous which makes RMA a nightmare.
good UK companies that I use:
Ebuyer.com (very dicey site lately, database seems to be complete bollox)
Aria.co.uk (small stock, prices vary)
there are others
Intel core I7 920
6GB OCZ platinum 1600
Samsung 1TB F1 Spinpoint
Samsung SM2443BW 24"