Hi Joe! Holy cow that looks like 10 times better than anything I have ever put together. How did you make the holes for the bus bars in the lexan (or whatever it is?)??? I quit sending lexan with kits since so many people (including me) had a horrible time cutting it.
Check this out for a relay that is triggered at a particular temperature:
Temperature Relay and Switch Sensor.
One of the temperatures is 104 degF hurray!