I would ask before you travel. Im not that up to date on UK stammering therapy but I do remember hearing about good therapists. Those that only try to treat repitions or whatever other stammer behavior you have I'm not sure if they are right for you. If i can remember any UK stammering people I know i'll send you their contact. I might start out by checking out the British Stammering Association and seeing what they have to offer or what resources they have.