Have you thought of the Long Trail? At 270 miles, it is easily a comfortable hike for one month. You get to do 100 miles of the AT in southern Vermont, then once you get past the Maine Junction you are in for a treat.
The terrain does get more difficult, but you’ll have 100 miles of hiking under your shoes by then. The northern LT is less crowded, has above treeline sections, a bit more remote and is (in my opinion) more beautiful.
I think the LT is a great way to sample many different aspsects of New England hiking. Even has a mini-Mahoosuc notch called the “Devil’s Gulch”.
Re-supply is pretty easy as well.
For more info go to:
http://www.greenmountainclub.org/EndtoEnd.htm
Mags