I don't have a specific chess set mold to recommend but 2 important things to look for are the number of pieces in the set and whether it's a fully 3d set or just a half mold.

A lot of the mold sets for chess pieces only have one mold for each type of piece for a total of 6 molds (example here) which means you can't make the full set at one time. Considering that each side has 8 pawns only having one pawn mold is a bit ridiculous and will result in it taking several extra days to actually make the all of the required pieces. And that's not factoring in the added complication of trying to color match the pieces for each set.

There are also a lot of mold sets that are set up so that all the pieces are in a flat mold and you are only pouring half of the piece like in this example. Theoretically you could glue the pieces together to get the full piece but that can be annoying to deal with especially if you did any special effect looks that you need to match between the halves.

In contrast to those you can find sets like this or this that have the full 16 pieces plus a board and a checkers piece mold. You will still have to pour the pieces for each side at different times however you can do the full set for the side at once.