I didn't look for a specific plant but they have a lot.

Here is a link that might be useful: Native plants

I came across this site recently. Don't know whether there are any natives lurking here, but the quantities are certainly there. Perhaps you can fill in with some of these until you acquire the plants you really do want.

Also, I have heard good things about Blue Meadow Farm in Montague, MA. When I finally found their website, I discovered they are going out of business and will be having a wonderful plant sale in May. Here's their address:
http://www.bluemeadowfarm.com/

Here is a link that might be useful: Green Mountain Transplants