You can buy those ranco controllers and wire them yourself and control any heater with them. I'd suggest doing that and getting two Jager 300s. I'm not completely sold on the titanium heaters. From what I've read titanium is a bad heat conductor, so I'd think that means it blocks a lot of heat inside of the heater instead of passing it to the water making it very inefficient. That might be why I only have seen them offered in 500 and 1000 watts.