While I can't speak for boas or their prey drive, I have two ferrets, a ball python, and several different species of lizards. It is NEVER a good idea to introduce them to one another (and I'm not under the impression you'd toss a ferret into a BCI tank or anything, just giving you some points to consider). Ferrets are super curious and get into everything. If a reptile is on the floor, you can be sure a ferret is going to check it out. Younger ferrets especially tend to be excitable, tenacious, and nippy. Once they discover something, they'll try to do it again and again. Regardless of a BCI's size or temperament, a ferret could do some serious damage to it.
That's not to say ferrets don't make great pets; I've never had trouble managing ferrets and reptiles in the same apartment. We just take extra precaution when either species are out. Tank cleaning is done when ferrets are away in their cage, reptiles are handled in a secure room while ferrets are free range in the rest of the apartment. With such limited opportunity for interaction between them, neither species seems overtly curious about the other.
My python doesn't seem to behave any differently when the ferrets are out, not that he could ever hope to eat one. They're weasels, not rodents, so I think it'd be about on par with a BCI checking out a small, goofy cat.
Good luck building your menagerie! And if you do go for ferrets, get two. They need a ton of attention, and ferrets can play with each other while you're unavailable. They won't be any less socialized in groups.
