You can certainly change the form that displays in the report by:
  • Tools > System Utilities > System Options
  • Under Section: select AP
  • Under Option: select Form1099
  • Click Lookup to select the form
  • Click OK

If the Value is left blank then it will use the User Defined 1099 Form, if it exists, otherwise it will use the System Defined 1099 Form.  Otherwise enter a custom form you have set up.

When running the 1099 report, you can now also select a different form.  Setting the default in system options saves you from having to change the displayed value each time you run the report.