I've been meaning to post this.....
A distributor called Americatessen provide American food to different stores in the country, and if you call them, they will give you the names of places in your area that they deliver to. Their website is
www.americatessen.com.
Also, a garden centre in Bagshot, Surrey called Longacres Garden Centre stocks some American stuff like Graham Crackers, Goldfish crackers, Fruit Loops, Lucky Charms, Double Stuff Oreos, Duncan Hines cake mixes and frostings, Aunt Jemima, Jiff peanut butter, A & W root beer in cans and 2-liter bottles, and more. The stuff is outrageously expensive, but most places that sell it are.
AND,...there's a sweet shop in Reading, Berkshire that sells some stuff, mostly candy, cookies, soft drinks, and cereals. I got the info on Americatessen from the woman who owns this shop. It's called Strange Sweets, and if anyone knows anything about the layout of Reading, it's in the Harris Arcade on Station Road.