Rebel Aircraft Grade Plywood is of the best available quality for a low price. Available in the sizes you need, up to 1 square meter. Thickness ranges in 1,5mm, 3mm, 4mm, 6mm, 9mm, 12mm, 15mm and 18mm, just what you need to built that project. We can make custom centering rings up to 1 meter across, so that should be adequate for your needs.