Plus one on the recommendation of Clive WOOD!
I'm one of those that has trailered a bike - two, actually - from Devon (a 500 mile round trip) for servicing simply because he is the best. You get to see, hear and understand exactly what he's doing and why; have the chance to know more about your own bike and what YOU can do in the future; meet his lovely wife and be served coffee and a sandwich. And, for me, just standing next to his former race bikes was a privilege in itself!
I've also heard many good things about "Muddy Sump" but can't speak from experience.