All the schools you have listed will be full of students with a passion for knowledge. My son, who wanted to be surrounded by more unconventional thinkers, chose Grinnell, but he was also interested in Oberlin and Reed from your list. Another great option we visited (but he didn't apply to) for an older learner is Evergreen State in Olympia, Washington. We also visited Sarah Lawrence. Clearly that is also a great school academically. It seemed to me like a less tightly knit social community than Grinnell or Oberlin.