Client-facing test plan documentation

We have a need to create Test Plan documentation for our clients.  These have to include detailed sections on the purpose and scope of the project, the test phase (including diagrams), test equipment set up etc., as well as the test cases and their steps.  This test plan format is mandated by our clients. 

These documents are currently written manually in Word, with the result sets in spreadsheets or Word.  We're trying to move to away from this to a proper test management system with Zephyr Enterprise.

Does anyone have experience of creating a test plan like this with Zephyr Enterprise?  Or suggestions as to how we might accomplish this?