CMS act_as_tree and modular architecture

I am developing a CMS using act_as_tree for the pages and act_as _list
to order them (as shown on Railscasts). Each page can load a custom
ERB template, for instance I have one to display a standard article
and one to display a group of articles (so acting as a category of
underling articles).

If I want to develop a forum, let's say that I have a page with id 5,
with name forum, how can a load a module component as module inside
the content div? Shoud I create a different controller and create a
route mapping /pages/5 to /forum?

As you might guess I am a Rails newbie.

Is Rails Cells what I need?

http://cells.rubyforge.org/