It looks like you have a solid setup planned for your U.S. selling operations. In addition to 4"x6" shipping labels, you may also need 30-up Avery-style labels (1"x2-5/8") for FNSKU barcodes if you’re sending inventory to Amazon FBA. Depending on your workflow, you might also consider a thermal label printer for barcode labels, poly bags for certain products, and a tape dispenser to streamline packing. If you’re doing wholesale, GS1 barcodes might be necessary for certain listings.