For anyone interested in a new backgammon board, the ‘Merchandise’ sub-section of the U.K. Backgammon Federation (UKBGF) website is probably the most suitable starting point.
This gives links to several renowned board makers, including Geoffrey Parker whose boards are used in many major tournaments worldwide.
Geoffrey Parker also sells accessories like dice, scorecards and a timer.
For a bigger range of supplies, often at cheaper prices, Chris Ternel’s U.K. based Backgammon and Board Games Shop is a good online source.
For those wishing to see boards and accessories in a fairly local shop, there is
Chess & Bridge at 44 Baker Street, London W1U 7RT