Virtuemart product update with custom report

We have a Virtuemart store with around 3000 products. We need to import a CSV file to update prices and stock levels using four columns: SKU, Price, Manufacturer and Stock Level. That is simple enough.

What I need to do as soon as the update is done is provide a report with two lists:

1. A list that reflects any SKUs/products that are currently on the site and associated with the specific manufacturer (there will be only one manufacturer per import/update) that was not in the CSV file. This would point out old products that should be removed.
2. A list of all SKUs/products that are in the import CSV that are not already on the website. This would allow us to find new products that we may need to add

Is there any way to do this using your product or could you offer a customized solution to do it?