I have tried lots of configurations. Here are some lessons learned:
1. If your room is not heated, and you're keeping boas/pythons, use either a radiant heat panel or else a heat bulb or two. If using only one heat bulb, you may want to run some Flexwatt under the cage as well. Depends on the wattage of your heat bulb and your ambient temps. Just for comparison, I used a 75 watt red heat spot lamp and a strip of 4" Flexwatt the length of the cage in the 3ft arboreal Vision. With that, I kept nice temps for a boa.
2. For kings/milks/corns/etc, you can usually be OK with just Flexwatt alone.
3. Temp control is a must. For non-light-emitting heaters (heat panels. ceramics, heat pads, Flexwatt) a proportional controller is best, or else a dimmer PLUS an ON/OFF controller. Home Depot sells a nice little tabletop dimmer that you can plug into an ON/OFF controller. Alife has a nice ON/OFF model. The Boaphile setup (Ranco tstat with outlet strip alreay wired for you) is very nice. I make my own just like that. Super handy.
For lights, use the dimmer/ON/OFF thermostat option.