Now I will admit to a full gear bag on my roundabouts in NYC. But nothing Like this.
Honestly, you can live without flash in daylight. More than one camera is just ridiculous unless you are shooting both still and video in different cameras. And DX Nikons saves you weight over FX. For a shoot like this I would probably just use a fixed 35mm lens and set up shots by moving back and forth. Or use and 18-55 for zoom.