We have purchased a TT in the US and are considering bringing it to the UK.
A company in the UK who sell our brand of trailer here and in the US told us they would do conversion here and if my memory serves me right they quoted ?2000. This may be a bit pricier than in US or getting a non rv dealer to do it.
We reckoned around $2000 to ship back to UK plus import duty, but a quick look on a UK website show's between ?2500 - ?3500 to ship to Australia. Here is a link to a different website that shows costs to ship a car as an example:
http://www.autoshippers.co.uk/AutoShipping_USA.htm
We are thinking about touring Europe in the future and as they drive on the same side as the US, our set up should be ok. But in the UK I believe all the facilities will be on the wrong side. Door, drains etc. This may not be a big problem for you but something to think about, if the door is on the opposite side from your picnic table you will have to walk all the way around your trailer and I could see that getting old pretty quickly, but I'm sure lots of people do it.
You would also need to check braking system as I believe there are different requirements between UK and US.
I think you could potentially spend quite a lot to get something from the UK. If you spend a wee bit more time researching you may find something similar in US for less money. That trailer does look lovely though ;D
I'd you'd like me to make any phone calls on your behalf drop me a message.
Good luck in your search.