So i want to know if i bought a phone from ebay in the USA would it work in the UK?

HELP? I want to buy a Sidekick LX 2009 but they dont sell them in the UK? so i wanted to buy one off ebay from the USA, It is unlocked and everything but would it work over here or would i need to do anything for it to work over here? also can i buy it in the UK, Im sure you cant? Thankyou and HELP?!