Customizing the invoice?

Hi folks, just curious about a question I couldn’t answer and didn’t find any threads on exactly how to do it on the forums. What we’d like to do is have the invoices sort the products by sku to help out our fulfillment side of the business to make it faster to pack the boxes.

I can’t seem to find any way to do this in the admin panel. Is there a way to sort it ascending / descending by sku on a template itself?

I would also like to know how to get invoices to order products by sku.