MMario is correct, McVities digestive biscuits are the nearest equivalent to Graham crackers (and IMHO a superior product).

When in Britain, try not to refer to well known cities followed by their country, e.g. do not talk about "Paris, France" or "Madrid, Spain" and especially not "Glasgow, Scotland". The assumption is that everybody already knows knows where these cities are.

Best of luck and welcome to Britain.

Murray