I am looking for quality foam manufacturers/suppliers for seat/chair cushions and pillows. US/non-US based both will work.
Alibaba.com - great resource with price ranges and minimum orders shown. If you know what you are doing you can usually negotiate to the terms that you desire with the prospective supplier.
Let me know if you want to jump on a call and find the right supplier together.
I would contact people who are in your business to see who they use and ask what their customer service is like. I believe that a referral is a much better way of making a lasting business connection then just using the internet. Great people help make greater businesses.