Hi,

You can generate separate invoice for Incoming shipments by partially receiving products by setting Invoicing Control as "Based on incoming shipments". This will create incoming shipment for the Purchase order you confirmed. After that receive product partially and create invoice for that specific product only.

Hope this may help you.

You can create multiple layout of invoice go to the technical settings-> action-> Reports copy Invoice Report and give the name whatever you want than go to the action binding search invoice again copy it and make changes in action usage please use your newly created report