Need a site that supports 1000 members

Hey WP pro’s – got a question regarding a big site challenge:

Situation: Need to build a site for 1000+ members with profile pages. Imagine a company where each salesman has their own page. The profile pages will allow them to post information, links, videos, etc. on a single page with their own url off the site. I also need logged in members to have access to other areas of the site based on their membership level.

Question: Do I use a membership plugin from a place like iThemes, or something like BuddyPress? People need to be able to register, fill out their own info, upload their own pics…all of that stuff without me being involved. I’m worried that a membership plugin might not be able to do it, but if one could, that would be less weight than BuddyPress probably.

Really appreciate any feedback!