Looking for bulk purchase of organic matcha powder for my health and wellness business. I am specifically interested in acquiring high-quality, sustainably sourced matcha powder in large quantities. The ideal supplier should be able to provide certifications for organic sourcing and details about the matcha's origin. Please ensure that the minimum order quantity is 50 kg, and provide information on pricing, shipping options, and lead times. Your response should outline any available samples for quality assessment before purchase.