I’d imagine Williams, Amherst, Bowdoin would be at or near the top of the NESCAC list. (We looked at them twice, once for a science student, once for not a science student.)I love Bates, and they are building a new science center. It can be nice to have brand-new lab facilities.
Dickinson in Carlisle, PA is a NESCAC-type school. We know a recent bio major who was going on to med school. They had great opportunities there. Lafayette and Franklin & Marshall, both also in PA would also be similar.
What about a mid-size (4k-8k undergrads) national university? I think schools like Rochester, William & Mary, and Tufts (a NESCAC school) offer LAC-type experiences with great research opportunities. (And Williamsburg has great weather and new science facilities.) Case Western Reserve University (CWRU, “Crew”) and WPI are mid-size STEM schools. WPI, in particular, feels like a STEM version of a New England LAC to me. WPI does have a particularly hands-on, project-oriented approach that may or may not appeal.
Good luck!