Well forget thermometer! you got yourself a thermostat! on right path next go to a local harware store and buy a I.R temp gun rougly 20-80$ depending on brand. what you want to look for is

-Min/Max(reading)
- 1.5+/- (don't want anything more then that for accuracy)
-and .5 +/- accuracy reading (meaning if u shoot 500 times, itll all be withing .5 degree)

Secondly for your hygrometer, an analog one will be fine, you dont need PERFECT 70 degree humidty like you need a steady temp, So just use it as a "guideline" when hes in shed make then needle go high, when hes not it can be mid to lower. it all depends on snakes, some of my 1 piece shed in 50-60 others 80+


That's just my 2 cents, thermometers are good if left in enclosure because they time for there readings, my Temp gun has served me well for the 30$ it costs! best investment other then herpstat! or well snakes themselves

Good luck!