Hi Stephane,
Below are some suppliers you might be interested in working with:
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To find specific products on their sites, I recommend using the search function and also make sure you contact them directly (can do this via SaleHoo) in order to get their true wholesale pricing which is always better than you will see on their site. When doing this, provide them with the quantity you are ideally looking for, where you want them shipped to, and how often you plan on purchasing - this helps gets the best possible price.
Hope this helps you out and if you need anything further just sing out :)