@jon.correa by scripting you may be able to do it, I have done similar consolidation with invoices to create a consolidated invoice from multiple invoices or SO. Used a saved search to get the line item then via scripting(suitelet) ported to custom record to hold all the selected line items then pushed the consolidated line items to new invoice. In your case it would be little different it will PO instead of Invoice also less tricky since PO does not have any GL impact.