Hey Mitch, welcome to the ball python world.
Most large scale breeders will keep their bp's in what is known as "rack systems". Predominantly, these tubs are heated by an external heat tape (attached at the back of the rack). If built correctly, it is completely safe to house your ball pythons this way.
Basic Rack System: http://ball-pythons.net/forums/showthread.php?112432-Completed-41-qt-Sterilite-Rack
Heat Tape: http://www.cornelsworld.com/accessories/heat-tape/heat-tape-faq
Keep in mind that all heat sources must be controlled by an external device. This can be with something as simple as a hardware store lamp dimmer, although rheostats specifically manufactured for reptile use are commonly more dependable/accurate.
Tubs aren't great at holding in heat. And so, your main concern using these enclosures would be how warm your home is/how dramatically temps tend to fluctuate in your home. I use PVC's for my adult ball pythons and Rubbermaid tubs for my young-adults, juveniles and hatchlings. Everything is heated with an Under Tank Heater. If your home tends to remain rather cool, however, you may want to consider radiant heat panels to keep your ambient above 70F (ideally 75F-83F).
Rubbermaids do not melt if the UTH is controlled. Otherwise, under tank heaters do have the ability to melt plastic (sounds obsurred but I've seen it), as well as fry your ball python. All my Rubbermaids have 20-some pen-to-penny sized holes drilled into them for ventilation. If you drill too many, this can allow too much ventilation-- lowering your humidity to dangerous levels (ie: below 50%). If you make this mistake, you can simply cover the holes with tape. Not fancy but it works.
Tub Set-Up: http://ball-pythons.net/forums/showthread.php?113879-My-Plastic-Tub-Setup-for-my-Ball-Python
I use various sized enclosures for my ball pythons as they mature, due to this species being rather shy (and intimidated/insecure if thruster into too large an environment). Tubs or Rubbermaids are therefore practical and conventional to use during these growing stages, opposed to purchasing multiple expensive enclosures you will probably never use again.
Ball pythons require a light cycle of 10-12 hours/day. That said, we tend not to use heat lamps to produce light. Heat and IR lamps tend to dry out enclosures, and direct light is incredibly stressful for this nocturnal snake species. I simply use a timed external/room lamp to provide indirect/soft light 12 hours (summer) or 10 hours (winter) during the day. Adjusting light times depending on season is not necessary, however.
Ball Python Care Sheet: http://ball-pythons.net/forums/showthread.php?127203-Ball-Python-(Python-regius)-Caresheet
If you have any further questions or require clarification, please ask.
Take care.