Rhp wattage

[Mayj12]

Hello everyone, just signed up 5 minutes ago lol. I've been researching for the past 2 weeks on boa care. My little girl has been fascinated with snakes since she was 3. She's 15 now and has been asking for one almost ever since. So taking the plunge. I just built a 4x2x 2ft high cage out of melamine. Trying to get everything right before we go to a show in a couple weeks to pick one up. The question is, what wattage of a heat panel would suffice for this? I've seen people say 40 then others 80. Most cages they talk about are only either 12 or 15 inches high. Will those still be enough on a 2 foot tall cage? I just want to make sure I get this right to make it easy on the snake and on me Haha.