You can buy the original Magsafe adaptor, or use a standard travel adaptor. The voltage auto adjusts for use here. Cheaper option is the travel adaptor, neater and very nice look - would be the UK Magsafe. It's your call.
PS: You can buy the Magsafe from Apple Store online, or at Retail, or any other Apple Reseller - but then you probably already know that !
My advice? Buy the travel adaptor, and save the money and use it for something else.