There are many 220-Volt stores in major North American cities. Before I moved to Israel in 1997, I went to one or two of the 220-Volt stores in Toronto to find some appliances like a De Longhi Toaster Oven and even a nice little 220-volt Eureka Mighty Mite canister vacuum. And in my apartment in Tel Aviv, I found a gorgeous 220-volt version of a 1980's Eureka Dial-A-Nap upright! I am sure that the vac was brought over from New York because the owner of the apartment I was renting actually lived in Brooklyn.
I think that many vac-makers offer 220-volt versions of their vacuum cleaners especially for purchase by families moving overseas - many are connected to the US Army or the American diplomatic corps who work in embassies and consulates. By buying these 220 volt appliances before moving overseas, they can be ready to go once they move into their homes at their destination.
Here is a link to one of the stores in Los Angeles:
I love Gumtree, its like an online Carboot sale and all you gotta do is fill in the part: "Find a ______ in ___________" Search theres a DC16 for £40 in my area