UKInbound, formerly called The British Incoming Tour Operators Association (BITOA), represents more than 250 British tourism suppliers with 5,000 outlets across the U.K.
They’ve got statistics reports and a member search function that gives you some names, should you need contact leads.
Here is a link to their Tourism Board/Destinations link. When you click a name, it takes you to their contact info, etc.
Good luck.