Good luck to them. It’s quite the story.
I’ve read that Kubrick originally wanted to make Childhood’s End, but someone else already owned the movie rights. Therefore, he got together with Clarke and started on a different movie which would become 2001.
Considering that it took until now to make a movie of Childhood’s End should be an indication of the difficulty.
I`m still waiting for the Foundation Series, by Asimov.