Solar noon during EDT in Atlanta is about 1:45 pm and nearly 2 hours earlier in Boston. That's when the sun is due south.I'd take a left hand seat for a 2 o'clock flight myself, although the sun will be mostly overhead and directly head on. But by the time you descend into Atlanta, it will be on the right.

Here's a link to another cool sun position app on the web: http://www.suncalc.net