I don't use a heat lamp for my Ball because it's really unncessary. I have a heat pad that goes under the tank stuck to the bottom though. If ambient temps (air temps) are too low though then a heat lamp would be needed.
I also am using Coco Husk fibre as a substrate because it holds moisture much better and BPs need at least 50-60% humidity.
You should have 2 hides, one for the warm end of the tank and one for the cool end. (BPs can be very insecure and if they don't have a hide on each end of the tank they'll sometimes choose to hide than to regulate their temperature) Also a water dish, then decorations! Oh, and a thermometer and hygrometer are a must. (those dial types suck, get digital!)