How big is your ball and how much money do you have to spend on this?
I really like "Animal Plastics" enclosures. I use their 4'x2'x1' (LxWxH) T8 Enclosure for my ball pythons. I got the Flexwatt heating option which heats the right side of the cage and I keep my snake room at 78 degrees so the cool side of the enclosure does not need any additional heat. I use butchers paper as a substrate and have 2 Reptile basics hides (one on the hot side and one on the cool side). I have a large water dish (ceramic dog dish) in the center of the cage. The Flexwatt heating is controlled by a Herpstat.