Buying an iphone 6 in the US for use in England.

[MakingUpTheNumbers]

Im the planning to buy an iPhone 6 in an Apple store in the US to use in England.

I believe I need to get the AT&T one that's compatible GSM and 4G in the UK and Europe, am I correct?

 

[eastbayrae]

I bought one in the US on TMobile. It worked fine on 4G in Dubai with an Etislat SIM.