The sandboard I borrowed from a friend was similar to a normal board but base was similar to the laminate counter top material. I think the board was pressed plywood. Masonite slide pretty well also Not sure if it's as durable but that could be good for low cost and easily accessible as well.
Honestly seemed a lot easier and more forgiving than trying to make a real board. Maybe go with the line afterbang style. That might be your best best.