I have a Voyage Air guitar, bought on the recommendation of a couple of luthier friends. It plays well, folds into its own backpack and is generally pretty close to being in tune once the nut at the neck is tightened. Not sure how easy they are to find in the UK - I bought mine in the US at the start of a very short tour (at the end of which I was travelling home in style by Cunard rather than flying).