Former Merchandise Mart art fair exec Tony Karman has snagged starchitect Jeanne Gang to design Expo Chicago, “The Inaugural International Exposition of Contemporary/Modern Art and Design,” scheduled for September 20-23 at Navy Pier. He’s also got the Museum of Contemporary Art on board, bringing back Vernissage, the traditional opening night benefit event. And legendary Chicago gallerist Rhona Hoffman is on his selection committee, poised to pick “no more than 100 top tier dealers” to participate.