Several years ago I got a 6-gallon Smokey Lake water jacket canner. It's really fantastic. It's the electric model. The heating element has a dial thermostat. It's not digital, and there is a on-off range that is wider than I care for. A thermometer on the front of the canner reads the temperature of the syrup. When I first started using it I seemed to get a slight haze in my syrup occasionally. I decided to upgrade it with a digital thermostatically controlled switch on the heating element.
https://www.amazon.com/Dorkfood-Sous.../dp/B0088OTON4
It's great. It has a very narrow on-off range--I put the thermometer in the hole in the rear of the canner where you fill with water. You can hear the element cycling on and off, and it keeps my syrup at a precise temperature.