Disclaimer

The following devices are not UL listed, and may not meet federal, state, or local codes.  If you use the following information as a guide for your own gear, you do so at your own risk.

 

Here's a box from O.A. Windsor.  It's unbreakable hard rubber, and comes ready to accept the Neutrik PowerCon connectors.   It's not cheap, but it's likely the way to go.   You can buy the box raw, or loaded and wired.   I don't know if they make a box with more outlets.