Do you mean Hillcrest Amour? Tubers are available at Seatac Dahlias out of Seattle,
http://pages.prodigy.net/patheck/stock2/330hilcr.jpg
or Betty's Amazing dahlias SE of Seattle.
http://www.bettysamazingdahlias.com/hillcrest_amour.htm

Do you intend to grow them yourself? If so, you'd need to inquire about their average time to bloom and plan accordingly. If not, the only grower in the US I know that ships cut dahlias is Swan Island. They don't carry H.Amour, but they do have "Bride to be." Congratulations on your pending marriage. It will be off to a great start with dahlias in attendance!

Here is a link that might be useful: Swan Island ships cut dahlias