I wouldn't get a 40 gallon, they are terrible for BP's. tubs and PVC cages are a much better choice. Tubs and PVC cages hold in heat and humidity very well and will make your life much easier.
Here is some info on tubs and PVC cages
Tubs: http://ball-pythons.net/forums/showt...Basics...*DUW*
PVC Cages: http://ball-pythons.net/forums/showt...With-Pictures!
Half logs are possibly the worst hides you can use, as they do not offer any security to the BP. these hides sold at reptile basics are considered to be the best by many.
BP's are terrestrial so climbing branches are not necessary but are ok if you want one.
astroturf isn't the best idea. I personally use corrugated wrap for substrate, but paper towels, butchers paper, newspaper, aspen, cypress mulch, and coco-husk are all good choices.
You are also missing the most important piece of equipment. a thermostat to regulate the heating pad. unregulated a heating pad can easily get over 150 degrees. this is hot enough to kill a snake. It also can short out and start a fire. a thermostat is absolutely mandatory. Don't waste your money on the crap sold in pet stores... and don't ask them for advice. they give out terrible information about reptiles.
here are 2 good thermostats:
budget (should be replaced with a better one when possible)
http://www.amazon.com/dp/B000NZZG3S/...13134469453409
Best: http://spyderrobotics.com/
make sure that the thermometers that you get are digital ones. once again the stuff sold in pet stores is crap and a waste of your money. you should get one of these. they are sold at Walmart for $12 and measure 2 temperatures and humidity.
overall by not using a heat lamp and glass tank your humidity issues should go away. tubs and PVC cages hold humidity in very well...
You should give this a read: http://ball-pythons.net/forums/showt...ius)-Caresheet
As for where to get your snake. stay away from petco/petsmart. not only do they charge ungodly amounts of money for their reptiles, but they are usually unhealthy and underweight. Your best bet is to buy from a breeder and have it shipped to you (which is very common and safe)
Here are some good breeders:
Justin Kobylka (he is in Georgia around Atlanta so he is probably the closest to you)
http://www.jkobylkareptiles.com/
Constrictors Unlimited: http://pythonregius.com/
Ralph Davis Reptiles: http://www.ralphdavisreptiles.com/
There are also many people on this site who breed and are great people.
With any breeders, they cannot post all of their avaliable snakes in their site, so if you don't see anything you like, just give them a call or email. they will be more than willing to help you out.
As for cheap morphs, i would go with Spider, Pastel, Mojave/Lesser/Butter