There are several members here that have wood tanks with glass or acrylic faces. I always use glass but that is just my preference. The seal thickness should range between 1/16"-1/4" or 1.5''-6mm thick using spacers at the time of the acrylic panel installation. As for waterproofing the tank to seal it there are a variety of products and methods out there from epoxy/fiberglass to using pond liners.