I was wondering the same thing, and I have connections to Mazda UK.. after emailing with him for a bit, he told me that the 2011 UK front bumper, would not be a direct bolt on (though I'm sure you can make it work with some cutting/fabricating). I went on to let my buddy know that I'd be fine with that and if he could price out shipping. He said that'd be the most expensive part, and that if I did replace it with an overseas bumper it would void any warranty I had on my 2.
Just something to be aware of for anybody looking to do it.