Hey there,
First off I want to say that I am very impressed by how prepared you are and how dedicated you are to making sure you have everything in check BEFORE you bring the snake home. A lot of people jump into reptiles without much consideration and make a lot of mistakes (myself included), and this isn't fair to the animal. So thank you for taking the time to learn as much as you can before bringing home your BP!
Your tank sound like its a great size. for a hatchling this size will be too big. You can make it work my filling it with decor and objects to close in the space a little. Driftwood, plants and other decorations can make a big tank like that suitable for a small BP. As it starts to grow however you will need to start removing objects to ensure it has enough room.
The reason people don't like tall tanks is because it is difficult to regulate humidity with all the open space. With that said you should set up your tank now and keep an eye on the humidity reading to ensure that you are providing the proper conditions. He're are some tips to help keep up your humidity (some of which you have already said).
-Water dish on warm side of the tank
-Mist regularly
-Wet towel over 75% of the lid to the enclosure (this is all I have to do)
They also sell humidity hides and fog machines to help but most of the time the towel trick is enough to keep humidity high. Humidity will always be an issue, but things like keeping the water dish on the warm end can be an easy and permanent solution.
The only reason I can think of for why tile works for lizards and not for ball pythons is their method of movement. Lizards have legs and can move easy over those types of surfaces where ball pythons don't. Try going into your bath room and placing your hand flat against the tiles with some pressure and try sliding your hand, you'll see what I mean. In addition most people recommend UTHs (Under Tank Heaters) as a source of heat as lamps will suck up all of the humidity in the enclosure. Tiles will allow for little/ no heat transfer when using a UTH. Also, BP's need higher humidity than Bearded Dragons and without a substrate to absorb some of the humidity as it sits than you can possibly be looking at a wet environment which can lead to scale rot. There are a few more reasons that I can think of but you get the point LOL.
In my experience BP's spend most of their time in their warm hide and if you were to get a humidity hide I would recommend you put it on the warm side. Its important not to go to crazy on the humidity though because humidity reading 80%+ can result in URIs, scale rot and other nasty stuff
A lot of people do have 2 UTH's set on thermostats to regulate the difference in temperature on either side of the tank. I don't do this. I don't find that there is a huge issue with temps for me. I keep my home heated to around 65 degrees and the temps on the cool side always sit between 75 - 80 degrees on their own. Once you set up your tank you'll have a better idea and may have to look at other options.
Some equipment is very important. Here are some things I imagine you already know about/ have but just in case I'll throw some suggestions out there.
- 3 DIGITAL thermometers (1 for warm side, 1 for cold side, 1 for ambient temps)
I personally have 1 thermometer because I use a temp gun.
- 1 DIGITAL Hygrometer to test humidty
- Thermostat (rheostats are useless and nothing more than a dimmer switch).
- UTH
I stress digital equipment because I find that they are much more accurate than the other ones.
I hope I gave you some information you can use, if I left anything out let me know and I'll do my best to answer for you.
Cheers, and good luck with your Ball Python!