For temps, it is recommended to have the warm side in the range of 92-94 and the cool side at 82-84. Anything below 80 degrees can cause a ball python to go off feed, and make it more susceptible to respiratory disease. I keep mine at 84/94, and she is a fat little heifer.

If an undertank heat source alone won't get your warm and cool side temps in those ranges, you will need other heat sources. I use two heat pads underneath an iris tub to maintain these ranges. Instead of those junky "reptile" heat mats, you can use flexxwatt heattape. www.mgreptiles.com sells this as well as reliable thermostats(which should be used with flexxwatt) for a reasonable amount of money.

You don't need an extra light for a day/night cycle. If the enclosure is by a window, then that works just fine.

Since you are getting a baby, small, low to the ground hides will help him feel more secure and be more apt to eat for you(in conjunction with proper temps). Small(4" diameter) clay pot saucers(what the clay pot itself sits in-collects water) work well for hides. Knock a small hole in two of them, and place upside down with one on the warm side, and one on the cool side.

With the digital temp/hygro unit, you would place the unit itself, flat on the floor of the cool side, and run the probe over and place it underneath the warm side hide. OR you can get a raging case of OCD and buy two units like I did. Place one unit in the middle of the wall on the cool side and run the probe under the cool hide. This will read ambient and floor temps, and humidity for the cool side. Do the same with the other unit but place the unit on the warm side, and run the probe under the warm hide. It will measure the same. Now is that anal retentive or what?

Anywho! I think a good thing to do before setting everything up, is to disinfect anything that the previous snake touched. This is just for the new baby's safety in case your previous girl had anything that led to her demise. I would fill the tank up a bit with water and then pour some bleach in there. Let it soak for a few hours. If you have any cage decorations, put those in there as well.

I also had a question for you. That light bulb that was secured to the inside top of that board, was it inside the enclosure where the snake could touch it? If so, that is a very dangerous situation that the snake can get into and should be removed immediately. Lamps in general dry the air out, reducing the humidity for proper shedding(which can range from 45-60%).

Ok, that should be it. If we missed anything, just ask. Nice having you on the forum, and hope everything goes well with your new addition