i am personally skeptical about the advisability of fiberglass
insulation in a basement. fiberglass and moisture is not a good
combination. in a basement, you not only have to worry about moisture
from the house, you also have to worry about moisture from the concrete
walls.

IMHO rigid insulation is the way to go in a basement. there are a
number of options for attaching drywall. USG makes a z strip that
fastens to the wall and provides a surface to screw drywall to.


BTW you could go with a vapor impermeable primer on your drywall,
instead of plastic.