Ok, So I decided to send them an email regarding the "region change" of the existing USA Fire TV's,
I asked for my message to be forwarded onto the relevant team involved with the Fire TV for a more appropriate response,
Take of this what you will but they have told me that it will be possible, First you will need to migrate your account, Any purchases made will also transfer, Then once the device has launched in your country, in this case the UK you then need to look out for a firmware update.
They say they will put it up on their help pages.
So that's good news, Sad that it will be a firmware update but not unexpected, Guess I will wait till the time comes and consider my options. At this stage I could not give up my root