i am developing a similar thing that works as a component
so far i;ve been able to include body text from actual components by adding tags to the front end (template file)
the tags (html comments, start and end) are mainly to identify mosMainBody();
the function i use reads in the component via hte front end (index.php?option=com_something) into a string, sorts out the bit in between
the tags and ideally replaces the links in the component itself so instead of index.php?option=com_something it will link to index.php?option=com_mycomponent&loadcomponent=com_something, including all params passed to the original link.
i seem to be a bit stuck on passing the parameters, but i should be able to figure this out soon.
anyone interested can try the link to Virtual Office http://joomla.spacetubbie.nl
(i'm still testing!)
or let me know and i'll post some code
comments or ideas would be appreciated!!