if you already have a thermostat then yes you can use that one if the t-stat is set the same temp for the boa.

Just zoo med is expensive but good for tanks not cages. Ultratherms are basically felxwatt sealed to be water proof to a degree. I use hot glue to seal it in to stop pee to get under anything. I went through about 2 bags of glue sticks for that cage.