Without a doubt and not to knock other methods but the absolute best enclosure for keeping a small amount of reptiles is a PVC enclosure. Animal Plastics, Boaphile, Reptile Basics. They all sell similar enclosures. For an adult 4x2' x12 or 15" high are the way to go. Animal Plastics, I would recommend the T10, Reptile Basics the 2x4 15" Single Door Cage, and boaphile the 421d
Animal Plastics has the cheapest initial price and more customization options to the cage itself but they also charge up to $55 for shipping so factor that in. AP's LED light option is not on the site but is $40 and really nicely recessed in. Both Animal Plastic and Reptile Basics have LED light fixture options for supplemental lighting but neither are truly necessary.
Radiant heat panel (RHP) for the majority of supplemental ambient and cool side heat or even as the primary hot side heat if you have a decent house temperature year round. A UTH of either Flexwatt, THG, or Ultratherm heat tape/pads are not a bad way to go for belly heat to suppliment a RHP
RHP vendors are Pro Products or Reptile Basics
PVC enclosures are great because all these manufactures build them to be stacked so you can place them on top of each other if you get another snake or reptile.
Thermostats are either spyder robotics herpstat or vivarium electronics and if you go the two heat method the herpstat 2 or VE 300x2
Coco fiber such as Reptile Prime or even Eco Earth are fantastic medium for substrate in these enclosures. Reptile Prime is already loose, has dust removed and comes dry.
For clutter and natural decor such as branches, artificial plants and leaf litter, don't over look craft stores such as hobby lobby or michaels or even walmart. Home Depot and Lowes are also great sources for materials if you want to build ledges, etc.