The Drupal “cpanel” refers to it’s “control panel” and is in no way related to what you are talking about. Drupal is a CMS (Content Management System), and the WHM is just an addon (with which I am not that familiar).
check http://www.cyberscript.net for one example of the kind of thing you could run on DreamHost. That said, this is not a particularly good environment to resell in the manner you describe. For one thing, you would be responsible for all the actions of your subscribers - I suspect that would result in your account getting suspended/terminated rather quickly because of some idiocy one of your users committed.
I resell all the time, but I use a different mode where I provide no access to the server at all (just resell the bare hosting) to my clients, and I handle all interaction with the server.