Most
LFS will sell driftwood.
You will need to prepare it before you put it in your tank either by soaking for 2 -3 weeks or by boiling for 2 -3 hours
The preparation will remove much of the Tannins from it BUT NOT ALL.
you must be prepared for tannins to leech into your tank, this will lower your
pH as well as be slightly unsightly by making the water tea coloured but carbon will remove it for you.
The Wood contains I believe lignite which aids the plecs digestion not having it in the tank will not kill the plec.