美国采购需求：板岩蓝色屋顶板、镀锌亮片钢板、彩钢卷、镀锌钢板、彩钢卷、彩色屋顶波纹板

I am looking to procure steel billets with specific dimensions and a sizeable quantity. The required size is approximately 150mm x 150mm and 12 meters in length, and the total order quantity is 3000MT. Could you please provide the pricing details, lead time for production, and any available payment terms? Additionally, if you have any certifications or quality assurance processes in place, I would appreciate that information as well. Looking forward to your prompt response.