Best store to use is
http://wargamestore.com/ IMO. Always have loads in stock (I assume as they more or less next door to Cerberus in Liverpool) and are always great. Downside is they don't seem to stock No Quarter. In close second I go with
http://www.waylandgames.co.uk/. They are also very good and professional but I find their stock system to be a bit too hippy dippy with "available" not necessarily meaning they literally have it in the store, unlike the former.