It seems like that's good as long as you're using a reliable thermostat (they can also be doubled up to reduce the risk of overheating). What's the tape for? Tape shouldn't be used on the inside of the tank as it can get stuck on the snake and cause problems. Also, do you think you're going to need 2 heat mats? Are you going to put one on each side to control both the warm and cool side temperatures? If so you're going to need two separate thermostats.