after losing fish to stuck heaters i have done a home made controller using a ranco etc refrigeration electronic temperature controller.they are $50 for the basic controller on ebay..i purchase a 10' extension cord 14 gauge and cut it in half and connect to the controller..i believe the contacts are rated for 8 amps..1000w is alittle high..800w is probably max.
with the ranco etc i use a titanium 800w heater element.(any brand or wattage) as a matter of fact i use it with standard 300w glass heaters as well.i like the redundance of the controller with the glass heaters thermostat..i havent had any boiled fish since going to this set-up..i will attach a picture for refernce..