I guess it could either be a picklist or a packing list, but it's a per order list either way.
In any case, we'll have to go back to @jbw to get a quote on this. Jer, can you quote for a feature to print a picklist for all unprocessed orders at once, please?
Regarding ShipWorks, Zac, I understand that managing quantities isn't so much of an issue for you. However, for most retailers, they cannot have ShipWorks handle everything because without tendering the orders at the POS, the quantities do not get correctly reduced. Furthermore, if it's a webstore order as opposed to an Amazon one, ShipWorks does not handle payment processing in any way, so there is no way to alter the order total when you're processing it; this is common where, for example, one item in an order cannot be fulfilled, or where the shipping charge needs to be adjusted.