I'm not sure, but I think Keith Manheim is running a custom CMS.

The things you're talking about should be simple to do with any decent CMS. I agree that having a fresh tour with content that updates is a good thing, but honestly I think that for a high-performing tour, a focus on the selection of models and pics (and video clips) for the tour will yield the best return in terms of conversion. A fresh and changing tour that's based on a CMS will help, but quality promo vids, great pics, and an appealing design are probably more important.