Good luck and keep us in the loop.
Boas rock, but you want to start with a happy and healthy one. That's up to you to decide.
Both my boas do very well with handling; better than any of of my other snakes. I can not handle for a while and they are fine, or I can handle for a longer duration and they are fine.
45 minutes is a long time to handle. I don't really handle any of my snakes that long, except Behira sometimes (Ghost BCI). The only way I handle her that long is if she's either playing on her scaffolding/climbing station or she falls asleep on me (which happens often). She's that chill.
The other thing is that Boas are generally sweethearts, once allowed to settle in, and handled 2-3X a week, give or take, with gentle and respectful handling. However, they have a killer food drive. Make sure to hook train whatever boa you get. I can help with that, as can others, if you have questions.