It's been a code and coffee morning
From a presentation perspective, the problem looks easy. Any number of widgets for a page can be modelled to be presented as a complete web page. It doesn't matter how the data is put together, e.g. flat files, canned models, hard-coded HTML.
What complicates the problem is how the user creates and manipulates these widgets to their needs. I've seen enough back-end interfaces for various products to know it can be done. The Mailbrew interface, which has similar functionality, is how I want this feature to work.
Instead of sitting at the text editor and blindly coding my way out of this, I've been using my iPad to sketch out a few ideas of how widgets of different shapes will relate to the page, and how a page will assemble these widgets. The problem is starting to unravel now.
Might be time for another coffee.