Send Invoices to sellers on multisite

So we are thinking about a workaround for the global cart without supported chained payments.
And here is a question:
Do you know of a good way / an existing plugin (or a plugin that is closest to what's needed ) to send multisite sellers system generated invoices for products sold on Multisite Marketpress from the main store owner?
In some sort it's a subscription type model for a multisite, with a difference that sellers will get monthly invoices based on the total amount sold, which they'll have to pay to the main store owner by paypal or any other available method.
Thanks.