I spotted that Charlotte from Write Like No-one is Watching has one (you'll see it here) and I figured you must be able to get them in the UK. I then found them at Violet and Percy, yay!
I already have some letter banners from Violet and Percy and I love being able to create personalised messages around my house... we have "Good Vibes Only" in the hall and "Happy @ Home" in the living room at the moment. I can't wait to get started with the light box!!