I know what you mean.
There is
http://blackdragonpress.co.uk/.
They produce some more under-represented properties.
Like arthouse movies and such.
The thing is. Things like Alien, Terminator, Back to the Future, Star Wars... they sell. Other things not so much. Except your're Mondo. Then most people don't care an just buy cause its drymount Mondo.
Iam in a few commission groups at Facebook. Same problem. Open a group for a small movie or even a movie like Birdman. It's a long way to get the people together. If ever. But open a group for Kill Bill or Star Wars and such. In a few seconds the group is full.