21st amendment has a pretty good distribution in MA now - try Julio's in Worcester if thats close to you. I know quite a few places on the south shore have quite a few of their offerings. Marty's in Newton gets 1/6 barrels from them at times, we got the Golden Doom once it was amazing.
While we are talking about stores, Craft Beer Cellar in Belmont should have some of the harder to find stuff as well. I think I posted awhile back I find their prices to be off on somethings, but their ability to get the real hard to find stuff its worth shopping there from time to time.