Just finished replacing the prep board on my old Lang 60. Used a piece of HDPE 1" 48X48. Thought it was gonna be to large, but decided it's always easier to cut it down if needed. I had something similar previously that stated breaking down over 10yrs from UV.
The old board was 30X40 " and worked fine, but figured what the hay Whatasize it. Board is mounted on the wood box. I modified the box so that the side of it can be lowered to store wood and equipment with out having to remove the table. Rounded the edges with a router and plan to cut some slots in the surface to put knives and tongs in so that they are out of the way.
HDPE routes pretty easy, an leaves a nice edge
Trial run just to test it out, turned out that it was not to big after all
Nice big area to prep and cut up Q when finished
easy to work off either side and not get in each others way