Here is a simple, fun setup for a boa constrictor.



The inner LED, blue light is an Arcadia Moon Light, purchased from Light Your Reptiles.

It's waterproof and very compact.

The strip LED light for viewing is an 18" Home Depot LED. I would not use a 2 foot light in a 4 foot cage. It's too much light and I personally think subtle low light is more attractive. You can still illuminate the entire cage for cleaning.

As Cody stated, a RHP tied in with a thermostat would be best for your ambient temps.

Obviously, type of snake, and year round reptile room temps will help for giving more info.