Chris, if I was going classic plastic, there are only two boats I'd concentrate on for the region you have in mind. The Pearson 35 and the Cape Dory 35. The desgins are excellent. Seakindly, maneuverable, lively, very sturdy, SAFE and roomy enough to prevent family-cide. The keels on both boats are up to the challenges of groundings in New Engalnd. For the East Coast, I always recommed a drifter or a spinnaker to reduce the need to motor as these boats were built with the engines still thought of as auxillaries.
I've cruised on a Pearson 35 and loved it. I've owned a Cape Dory and still regret the day I donated it.