3D Models for Compositing

Here are a few websites  from where you can get your 3D models:

• http://tf3dm.com/
• http://www.turbosquid.com/
• http://foundation3d.com/

You can find great stock pictures (still pictures) here:

• http://thestocks.im
• http://unsplash.com
• http://littlevisuals.co

Here is something totally different. Green screen plates:

• http://www.hollywoodcamerawork.com/
• http://www.hollywoodcamerawork.com/greenscreenplates.html

Enjoy!
I am not associated with any of these companies.