I found one online store that stocks all of the legal FTC platic materials in the correct thicknesses.
ABS, KYDEX, PETG and Polycarb.
I ordered several 2x2 pieces of each type.
They have a minimum dollar limit, below which you get charged a small handling fee.
Maybe some close teams could place a combined order.
Make sure you select the correct thicknesses.
They have a cool camoflage Kydex, but it’s too thick. We had to go with plain black.