Not sure where you are located, but in just about every major city you should have a container company that would have a department that can assist you with everything you need. From Identifying everything that you would be shipping, to sourcing the right size packaging, to all the necessary materials you would need to keep your product safe in local to international markets. Even customizing a specific box, bottle, plastic wrap, plastic jug, milk carton or whatever your product needs
Most of these companies have very large clients and those company's rely on the expertise of these container company's.
I'm not endorsing but here are just a few of the larger ones:
Consolidated Container Company
Dart Container Co.