http://basschat.co.uk/topic/26654-recommended-luthiers/
There's some in this thread in Bristol. Obviously there will be others but I can't really help with that.
Just don't go to Emarty (now Weston music shop). I had my bass set up there, it took them a month and I swear all they did was change the strings. I was younger then, should have complained but I didn't.
Anyway, hope this helped