i think when it comes to caging for bloods, you really have to go with what works for YOU in YOUR situation.
I kept my bloods in rubbermaids and custom enclusures, with newspaper/paper towel for substrate with 60-75% humidity 79-80 cool end, and 87-88 hot spot.
Above you see that others use other substrates as well as different temperature and humidity ranges.
But theres one thing in common......all of them are healthy...well, im assuming everyones bloods are healthy
chances are ...someone in florida will use different housing then someone in moscow.
ambient humidity levels differ, temperatures of different seasons, etc... all can have an effect on keeping your blood happy.
so theres not one housing standard for this species.
And perhaps thats why your finding it hard to come up with some sort of recipe to follow.
personally, if you have previously used rubbermaids and paper towel for your snake(s) in the past with good success on maintaining humidity levels as well as ventilation and a healthy animal, perhaps thats the route you should go.
Others have used aquariums for years to keep there snakes in, and i have no doubt in my mind that someone who has used aquariums for 10+ years, and has housed numerous species of snakes, probably would not have a problem maintaining humidity for a blood python.
keeping a blood is similar to incubating eggs.
some ppl use hovabators with great success, others use coolers, some ppl use fridges, and guys like Roy Stockwell builds them out of wood...
Now.... give me a couple sheets of wood and tell me to make an incubator, i wouldn't have a clue where to start.
But roy has obviously had success incubating his eggs this way so why change?
Because he obviously knows that in order to incubate an egg, you need to have the temperature and humidity levels right, and all other things mean nothing.
Same goes for bloods.
Get the temps right, get the humidity right, provide the neccessities like water and hides, and whatever you choose to keep it IN and ON, is really what will work for you in your position.
Cages which i would recommend are rubbermaids, melamine enclosures, and plastic cages.
Substrates id recommend are newspaper or papertowel. and perhaps cypress mulch and/or spagnum ( if your dealing with low humidity levels).
Heating wise,... heat pads, heat tape, or heat panels.
You'll obviously want to use a thermostat with anyone of these heating devices, because rarely do they hover around the exact temperature you need them to be at.
So since you dont plan on getting it till feb.
find a reputable breeder who captive PRODUCED the bloods for sale, then set up the best enclosure for your situation and have everything running smoothly for a couple weeks. then buy your snake last.
In the time being, buy a digital thermometer with hygrometer.
Place it in the room where you would want to keep the blood.
check the temperatures during the morning, afternoon, night, etc....as well as the humidity levels.
this will give you a better idea of what your up against.
that temperature will more then likely be close to your ambient in the cage.
if your like my place, no corner in my apartment is less then like 80 degrees even during winter... or perhaps you live in an old house where temps are very unstable and can reach into the low seventies (or lower with drafts, etc..) where perhaps a melamine cage will aid in keeping in the warmth as well as using a heat panel to boost up ambient temps in the cage.....
See where am i going with this???
caging , heating, size of water bowls...etc... really depends on the variables you CAN'T control....
figure out that first....than come back and ask more questions...
hope this ramble has been of some use and not confused you even more...
Gvg