If I had more space, modeling skills, time and money, I would model The Put (Putnam Division of the NY Central).
It would include 2 ballparks in The Bronx: Yankee Stadium and the Polo Grounds. It would have Pocantico Hills train station (beautiful Victorian style train station near the Rockefeller Estate), dairy farms in Northern Westchester County and Lionel Postwar operating milk cars and platforms, a train station in Yorktown Heights (where I live), and an iron ore mine (Tilly mines) in Brewster, NY with lots of Postwar operating ore dump cars. The scenery would include the Bronx River and Saw Mill River, beautiful rolling hills, and the Gate of Heaven Cemetery in Valhalla, NY where Babe Ruth has his final resting place.
I think The Put could be an excellent model railroad for a train club. It would be great to make the model railroad historically accurate, especially since it no longer exists.