Do you know of the theatre "Bible" called "CONTACTS" ? Published annually in October by The Spotlight (ISBN 0-9539210-4-2) it costs 10.99 - I've seen it stocked in some bookshops or you can get it direct from Spotlight (Tel. 020-7437 7631) - and kept in larger public libraries, too.
It has full contact details for all UK Arts Centres, Community Theatres, Theatres including categories for Fringe, Provincial and Rep. Also contacts for anything and everything else you might be interested in (e.g. publicity, radio stations, recording studios, rehearsal rooms). Well worth the money.