Best approach to implement a content driven composition with InDesign ?

Hi,

I'm search for the best approach to implement an automatic content driven composition with Indesign.

My contents are XML based.

For now, I work with InDesign (Desktop app) and a scripting solution to handle CMS search and import in predefined InDesign templates or files with known pages number.

Tomorow, I need a solution to compose many pages on demand with an unknown pages number produced, a simple and repeatable InDesign template.

InDesign server will be used to do this job.

But how to use it ?

by handling IDML files  ?

by scripting ? an ImageCatalog.jsx based on an XML structure ...

other solution ? maybe a plugin ?

What's the best approach in term of performances, development charge and maintenability ?

Any ideas, samples, ... will be appreciated

Thanks