I just ordered several pounds of straight varietal tobaccos for blending from Pipe & Leaf. PipeandLeaf.com: Pipes, Tobaccos, Accessories - Pipe & Leaf
All of the ones I ordered are Cornell & Diehl products; Pipe & Leaf has spectacular pricing on these blending tobaccos, a good 30% cheaper than some of the competition.

If you are into blending tobaccos, where do you purchase them? What companies do you think produces the best blending tobaccos?