Depending on how many your looking for and how much $$$ you got to spend, I'd highly suggest checking out Great Lakes Hops -http://www.greatlakeshops.com/
Your buying hop crowns, the main root system, and not a rhizome, so they're a bit more expensive. But, you've got better chances of 1st year production. Also check out the Hops Growing section of the forum and the For Sale section. I believe someone named Helix.... something or other is selling rhizomes still and people are happy.