There was an article about desirable, affordable suburbs within the 2 months that was picked up by Yahoo, alas I cannot find the link right now!
But I remember this about it: ALL the suburbs suggested in that article were in New Jersey, and some of the towns are on Debbie's list. Arts specifically I don't recall, but I remember the photos of quaint, walkable downtowns. If I were you I'd contact Debbie.
The most art-intense place on Long Island that I know of, outside of the Hamptons, is Huntington or Huntington Station, there are major art institutions there. This is a trek to Manhattan. And I'm pretty sure Westchester has us beat when it comes to art galleries, film houses, and music performances--Nyack (artists) and Tarrytown (Music Hall) of course leap to mind.
Lic RE Salesperson (New York only)