Laminated wood from Boyds.
I STRONGLY second that! Doubt if you'll find any stronger. However, if
you first find that you are having accuracy problems because of the present
forearm, you can order a hanger bar & forearm from Virgin Valley. Get the
buttstock from Boyds, and order a laminated forearm from VVCG with the
hanger bar. (I'm pretty sure they get their forearms from Boyds, but the
forearm must have accurate routing done on it to accept the hanger bar.)