Yes, with ProWeb you can have any number of "alias" or "slave" domains that point to the same content. Check the ProWeb page http://www.jtan.com/proweb for details.
You can also have unlimted subdomains that point to differnet content. If you want different top level domains that point to different content, there is an additional fee. Check our pricelist at http://www.jtan.com/services/pricing.php3 for current pricing.