Mark,
I'm in Boston too. I just bought a Dandy Sillouette AC/De-Humidifier. This unit has 2 6" ducts that connect to a plate which goes in the window. 1 is an air intake, the other is the hot exhaust. This thing kicks butt! Works absolutely awesome. It was 450$ in attleboro, I think the place was called Percy's, not 100% on that tho, it was next to BestBuy right after the Emerald Sq. Mall. Here's a link to what I got.
-Brian