@paulb - I don’t have specific recommendations, but I can offer a technique. I put a small power strip inside my mirror that powers the Pi, monitor, and LED accent lights. The cord to the power strip is plugged into a smart outlet, which I can access via Alexa or the mobile app. One command shuts off the power strip and anything plugged into it.
I think I’m using a WeMo smart plug, but I have like five different brands in the house.