You may wish to look into elementary feeder districts that send their students to the New Trier Township High School District 203. Outside of Walter Payton and Northside Prep (Chicago Public Magnets), it is the highest ranked public school system in the suburbs, if not the state. The North Shore communities include: Winnetka, Glencoe, Kenilworth, Wilmette, Northfield, and portions of Glenview and Northbrook. The communities definitely have a suburban feel with very few apartments/condos. The quality of education and the parental involvement are outstanding. The downside is that the housing is exceptionally pricey, many people don't care for the 'homogeny' of the neighborhoods, and there aren't a lot of cafes/bars/shops to walk to like you have in River North. There are several convenient Metra stations and the ride is only about 30 minutes to downtown. Depending on what time he would leave and what route he would take, the commute can be 30+ minutes (Edens or Lake Shore Drive).
Evanston is also a good district with a more urban feel and significant diversity (race/ethnicity and socioeconomic). It, too, is a North Shore suburb.
Others have mentioned Oak Park/River Forest - another outstanding school district still with that urban feel. One can easily access the Eisenhower, Metra, and CTA.
I'm a high school teacher, so feel free to ask questions and I'll give you my biased opinion *chuckle*!