[Simon]

Vivaldi, I believe the "server edition" of TGPX will do what you want (if I understood what you wanted that is). It's more expensive than the standard edition but it allows you to run multiple sites as long as they're on the same server.

As an alternative, depending on the script you choose, you may be able to make a template that contains only the listings and then use SSI or PHP to insert the content into another page on another domain.