Hdmi is the same whatever
A cheap one will do, dont let people in currys say it makes a difference, it doesnt
Really cheap ones can be shit, but certainly the shops that sell Monster cables for 50 quid+ should be prosecuted.
These will do the job, donkey, good quality cables, good shop all round in fact, and cheaper than anything you'll get retail (inc the Tesco value cable end of things):
http://www.hdcable.co.uk/cheap-hdmi-cable-hdbasics.html