Kinect with Processing on a Mac

Hi I have an interactive project which I now need to implement Kinect on for the client - it's to allow for gesture / finger painting type interaction.

It was built in Processing 3 on an iMac El Capitan.

Some questions:

1. Which library do I need ? OpenNI ? is it compatible with Processing 3?
2. If it's not possible to develop on a Mac - if I develop on a PC - will it still run on a Mac if exported as a stand alone app?
3. What is the best Kinect model to get?
4. Do I need any extra cables?

Thanks for any help, Glenn.