If you utilize a moat, wood would be fine. Otherwise Fulings and Lox would destroy wooden walls fast.

I personally have 2 Plains bases. 1 it's mostly stone. The other is a mix. Both have moats.

Just keep in mind deathsquito's can get over any walls. Mine are 2 of the large stone pieces high and they still come over it.

If you make a pen for wolves or boars,etc, be sure to put a roof over the pen. The skeeters will make a beeline to the pen to kill them.