I'd first look to a relay solution as it can give you much wide power source options. If you go to logic boards, you need clean steady power.

You might want to spend a little time looking at the web pages of swimming pool supply companies. They'll already have components for doing the basic job of switching a pump on and off. Looking at their equipment might give you the clues to find the companies making their fixtures and components.

And you get the additional advantage of seeing solutions designed to operate outdoors.

aka J