BE CAREFUL!!!!
A proper "hot" snake cage is very secure.
You should build an "escape proof" cage, then put that into another locked "escape proof"
Since they need low humidity a screen top will be healthiest, but not the safest. Make sure there is at least 2 layers of screen with the minimum distance apart being at least double the length of adult fangs of your species.(they can strike through the srceen)
It is expensive but you should stock the appropriate antivenin and have medical quality information to bring with you to the hospital.
The room with the "hot" cage should be totally sealed, with the door having a sturdy skirt and solid threshhold. All air vents and windows should be covered with strong metal mesh.
The door should be labeled as containing venomous snakes. (if your house catches on fire and a herp friendly firefighter tries to save your snake, he should be aware of the danger)[worst case scenario]
You should have a clear plan to deal with any potential escapes or bites.
Venomoid snakes should always be treated as venomous. Most vets won't preform the surgery, so they are usually done by herpers with a lot of experience. That being said, venom glands are difficult to remove, and mistakes do happen.
If you are serious you should first get a 6' agressive snake and keep is like a "hot" snake for a year or so. You may change your mind.
Good luck, be careful