1) A thermometer doesn't regulate temperature, it just measures it. A thermostat regulates temperature.

2) Both snakes need their own homes, cohabitation is risky. Ball pythons have been known to eat each other, if one gets sick then the other one will as well. A 30-gal will work for a while, a 40-breeder will work for life. If you'd rather go easy-keeping look into a tub/rack setup.

This thread shows you how to set up a tank: http://ball-pythons.net/forums/showt...-With-Pictures!