Commissions Reports: Visibility of Gross Profit & Sales Team Member %

I am doing the normal hunt-and-peck in reports to try to find the fields I want in commission reports.  First, there seem to be two types of reports with the following tables:

1.  Commissions Overview + Sales Rep
2.  Paid Commissions + Sales Rep

I am trying to figure out how to have the following fields appear on either report:

a.  Gross Profit ($ or %).  Source Opportunity sub-table has this field, but seems to show nothing?  What does this draw from?  In the Commissions Overview table, there is a Transaction sub-table that has some fields but is missing the Est Gross Profit field !?!?!

b. Net Amount Collected on a given Invoice (driver of the commission by collection; we have team selling so "base amount" would otherwise work but in this case base amount is the net amt collected x SalesRep% on the Sales Team tab.  If I could isolate the sales rep % on the transaction in the sales team tab I could back into it but I can't find that either...).