I have a School for Scoundrels Table that has warped due to the fact that the dice stacking laminate was only applied to one side and left a unbalanced panel that warped. My first thought is to build a new panel correctly, (balanced) but have no idea what is a good material for the surface. My other option is to build a metal frame and I don't think that will give me a nice flat surface.
Any help would be appreciated.

My dice stacking "board" is simply hardboard with formica glued on top. I put a small wooden frame around the outside. The board area is the same size as a close-up mat. That way I can perform on the mat, lift it and perform dice stacking. Another alternative would be to have the pad on one side of the board and the formica on the other.

Dice stacking also works well on the smooth metal covered hot dish pads (large) used in the kitchen for hot pans on counters and tables.

Believe it or not, in the 70s it is the only thing I ever saw used for that.

I cannot remember the name of the Dick Stacking sheets recommended by Mike Rogers. I bought a sheet at the local Industrial Trade Show company here in town. I was a brown material laminated between smooth material. I believe the name started with a "B", it has been a long time. I don't know if Rogers' mentions it on his DVD on trade shows or not, as a friend told me the source, he worked for the Trade Show company. I was really great material, not marking left and did not burn or damage the lip of the cup.