How to collate information in order to produce and Intermediary report

There are 2 options here then.

You should use suppliers and just list the totals invoiced/paid to them from the suppliers list by doing an advanced search:
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The other option would be to use project tags, and add a project tag for each contractor (and even job if you wanted). This can also be done to view totals on a date range:
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There’s more info on projects here: Projects in QuickFile