Nope. Unfortunately I haven't actually spoken to any of these actors...yet. Perhaps one day, once I'm in the business, I'll get a chance. Of course in that case I'd mention at some point that there's this virtual series, for which I've cast them.
The truth is, you don't need to get permission for something like this. In fact, there are a lot of virtual series out there, who have "cast" actors for roles. As long as you're only using pictures which are available for everyone, there's no problem. What we could not be doing, however, is use clips from say 24 or any other show or movie that the actors have been on. That would most likely bring up copyright problems, since we'd be using another show or movie to advertise something else. We'd need to have the permission to do that. As long as it's just pictures and the imagination of the writers and readers, there's no problem there.