My first thought for you would be to find a fulfillment center that can handle your needs. Rates vary and includes the cost of receiving, storing, packing, and shipping to your customers. Cost vary but the three centers I would start with would include: ShipBob, RedStag, and FBA (Fulfillment by Amazon).

Hope that gets you started. Let me know if you have any other questions.

Mario Ashley
www.marioashley.com