I'm currently looking into this option as well. I will be running two 500W finnex heaters. They don't have internal control, but will be putting them on apex, however, I'd like a second level of protection. On my other tank, I currently use two finnex controllers and those have worked well, but considering new options. I don't love the look of the inkbird 308's, but don't mind the look of the built in type ones. It seems the wiring is pretty straightforward and I can get whatever probe I want. I also have looked at the Ranco, but which model are folks using? Is there one model that can control 2 heaters?