Chris, the point of Distrify is that they're not trying to set up just another portal, like many tried unsuccessfully before them. The point of sales can be anywhere where the player appears.
You can see all films currently using Distrify at http://distrify.com/films – but that's really just a list for reference, not necessarily targeted at the public.
Instead, places like The D-Word could be exactly the sort of website you're describing, at least for the documentary world. It'll need a bit more work on curation, design, and editorial content for the public part of this site, but that's what we're already working on. Stay tuned! :-)