Hi Jesse:

I'm not sure if this fully addresses your requirement. One way to do this would be to use barcode scanning to select the product and then click on the "Replenishment" button on the product template to specify the quantity and automatically add the product to a Purchase Order. You need to make sure that the vendor has been configured for each of these products in the product template. 

This will keep "collecting" the replenishment requests in one Purchase Order for each vendor. The PO's will then need to be verified and confirmed manually at periodic intervals. This has been done to optimize the procurement process so that you can send a consolidated PO to each vendor instead of one PO for each item ordered.

You will need some level of customization if this whole process is to be automated to make it a single scan process.