Hey Ipstenu, I just wanted to give you a shout out and thank you very much for the advice. I decided to set up my site as a network, with the main site (for the general public) using the stock theme and a member community site using BuddyPress. Finally, I installed Private WP on the community site to restrict it to members only.
This setup is going to work very well for my client, as they like the social features of BP but didn’t want their public site cluttered. Your advice was terrific. Thanks again!