They might not be the best snakes for handling.
Maybe get a colubrid to handle? My cornsnake doesn't seem to mind. Ditto, the Sonoran gopher. The Sonoran started out rather twitchy as a baby, which made ME twitchy. She moved a bit differently anyway, and that took some getting used to. I handle her daily now, although it is over the cage, incase either one of us startles.
I don't own a proper boa, but they always look comfortable draped around people.