Drupal or CivicSpace?

I am in the planning stages of creating a community portal. Although I definitely want it to be a platform where community groups can set up their own pages, blogs, and groups, I'm also looking to having a general forum for all kinds of topics, a business directory, real estate listings, local school information, etc. Basically anything that you could want to know about our rather small town, I want to make it possible for someone to post it. I plan on supporting this site by selling advertising to local businesses and google adsense.

I am definitely going to use Drupal, and I was leaning toward the CivicSpace distribution as being the ideal starting installation. However, after playing a little with it on OpenSourceCMS, I'm not so sure that's the best idea. CivicSpace seems to be very focused on community and political organization, primarily. How difficult would it be for me to mod it into doing more (like the real estate listings)? Or should I start with a clean install of Drupal and build from there? I may not be interpreting how all this is supposed to work correctly; I'm a relatively new convert to CMSs in general and Drupal in particular.

Any advice on this would be appreciated.