It really depends on how complex/simple it cam be made, and the PID module itself. There are tons of panel mount PID controllers, I'm just not sure what everyone prefers ore regards as best of options like this -
https://www.amazon.com/gp/product/B08HGPXK1T or
https://www.amazon.com/Inkibrd-Temperature-Controller-100ACV-240ACV/dp/B08Y8F8QYM/ or
https://www.amazon.com/Display-32DIN-Digital-Temperature-Controller/dp/B079WKFVHV
If there's a community fav, that's what I'm looking for.