I am looking for reliable OEM furniture manufacturers who can provide high-quality products for a new line of furniture we are launching. Specifically, we are interested in manufacturers that can offer custom designs, have a verifiable production history, and maintain sustainable practices. The ideal partner should have a minimum order quantity of 500 pieces and be open to collaborating on design prototypes. Please include information about your production capabilities, lead times, and any certifications that demonstrate your commitment to quality and sustainability.