美国采购需求：足球机，足球训练机，羽毛球机

I'm looking to place an order for a set of balls, specifically requesting a quantity of three balls with a diameter of 20. I would appreciate it if you could provide me with details on your available options, including specifications, pricing, and any bulk order discounts you may offer. Additionally, please let me know the estimated lead time for delivery and any other relevant information regarding the material and quality of the balls. It's important for us to ensure that the products meet our standards, so any documentation or assurance on quality would be great.