I am interested in having a community type portal that also would allow (similar to Facebook, etc) each user to have their own subportal or page or whatever.

I am asking what is the best organization for this for efficiency and speed to allow the users of the community/forum established around a common theme to be able to develop their own page or portal yet still be directly linked to our main sight for purposes of e-commerce coexistence and going through us for access to income producing areas of their page and it being worth it to them to do it because of the draw we have, thus us receiving a little of their revenue from either seminars they teach (we provide the checkout and registration for the courses) or even selling products or educational modules for staff training.

Any organizational ideas would be appreciated using the modules available.

I am not averse to spending a reasonable amount of dough for a scalable portal for upwards of 50-100K users eventually with multiple interests but around a common theme that we continue to create the magnet and draw to our sight. 

ideas?

thanks

Frank