I am interested in buying a dwarf pyramidal form of Tsuga canadensis, preferably from a nursery or individual in the eastern United States.
lol, that shouldn't be too hard. There's several dozen cultivars, many are exactly matching your description, though Tsuga canadensis in my opinion, tends to grow irregularly, not like a Christmas tree.
Surely there are local nurseries near you that offer some of these plants?? If not, there are a dozen online nurseries that can help you.
Woolly adelgid - may wish to consider something other then hemlock.