To me, the city is about street shooting so one camera and one fast lens (35mm or so)......although if you hang out in Central Park, a small 3 lens set would be nice. You definitely want a fast prime lens. The city can be visually busy and being able to isolate people with a large aperture is a good thing. The other thing I'd do is to stick to fast color or BW. I tend to shoot a lot of Tri-X or Tmax-400 in the city.