Jill Zarin’s annual luncheon is upon us, and it’s set to be the most remarkable one yet. The Real Housewives of New York City star’s party planners Brian Kelly and Sean Koski chat exclusively with OK! about what goes into making the annual bash — which will take place on Saturday, July 20, benefitting the Bobby Zarin Memorial Trust in Southampton, N.Y., — a success and what will set this year apart from the others. “To keep it fresh, every single year is simple for us. We each travel consistently throughout the year, so being inspired by unique finds around the world is one way that keeps us l…