it looks like you said you are going to have your python and boa cohabitate. I honestly don't know for sure, but i suspect that may not be best for either animal, health or happiness-wise. Would be very interested to hear what more knowledgable members have to say on this. Regarding RPH's, they are great, but don't arrange them a way that the snake can easily touch it. They are not hot enough to instantly burn like a ceramic will, but they're still WAY too hot for the snake to sit on or against for any amount of time. In choosing, i would er on the side of bigger, you can plug it into a thermostat and/or rheostat to limit the output. Mine is plugged into a dimmer to keep the output just right, then the dimmer is plugged into a thermostat for redundant safety.