If villain is weak-passive, I'd buy in for as much as he has any time. Against someone who gets it in with a fairly wide range presumably, I'd feel much more comfortable with 100-200bb stacks.

Has he just never minraised anyone, or has he never raised and taken initiative post-flop?
tbh I don't see how the turn is a shove unless you have seen him try to get it in (betting) 200bb+ deep with one pair.