You can add the SKU in the invoice from the sellacious backend > settings > template manager. We will add the manufacture shortcodes too.
As for order view, you can add the details in this file components/com_sellacious/layouts/views/order/default.php
Please, make these changes in the overrides, so they won't be overridden.
If you want us to do it, you can order customization. This feature will take 8 hours of customization.
I hope this helps.