individual stores

Hi guys

I have a group of artists that are promoted by one manager. I want them to sign up on the manager's site (a drupal core site) and be able to create their own music stores (upon getting the right permissions).

These individual stores will be selling downloads (music, videos, screen savers) all media will have a preview, (audio & video with a 1 min clip; screen savers with a thumbnail)

Each artist will have their own paypal or payment gateway associated with their store, and a subdomain or url like website.com/artistname or artistname.website.com