Requisition, Purchase Order, Voucher query

Does anyone know if a good "view" or delivered report that will show Requisition, PO and Voucher data in 9.1?  The key is that the user wants to see what portion of the PO has been used up via voucher/payment, and what is still open.

Trying to tie together all of that into one query with the three modules seems very difficult, so wanted to reach out for recommendations. Similar to the PO Activity Summary delivered pages that show invoices, receipts, etc tied to POs.

Thank you!

Pete