Opportunity>>SalesOrder>>Invoice

Has anyone generated a single item-level report that pulls data from Opportunity, Sales Order, and Invoices?

- When an opportunity is closed-won, we create a sales order.
- On the sales order we set up billing schedules
- From there we generate invoices

In one single report, we want to see all scheduled billings (from sales order), actual billings (invoices) -- all tied to the original opportunity -- at the item level. 

For any given period, we need to see in one report scheduled + actual billings (this represents our billings forecast) -- with the original oppty/booking amount.

The views for Forecast, Sales Order, and Sales -- reports are not consistent in that we cannot easily locate oppty fields.  Any ideas/suggestions would be much appreciated.