I live in NYC too, I would go with the Pro kit. I have Steeda Sports with adjustable Konis, they have a similar drop to the Pro kit. I didn't go lower just because the streets and highways are horrible, I can feel every imperfection and bump on the road, and on bad roads, you will definitely be bouncing around in the car.
2014 Mustang GT, DIB, MT82, Tech and Track Package
mods are coming, slowly