Anyone had any success with creating either a custom report or custom saved search based on sales but also reference case records?  I haven't had any luck in custom reports and I know I can easily loop both sales and cases into a saved search but I like the report options for Monthly, Year, etc.

Here is what I am trying to accomplish:

1) Report should include all customers with sales created during previous month.
2) Of those customers with sales in previous month we need:
    a. Total Closed Cases in Previous Month


Thanks in advance for your help!

Jenny