Yup... the first arc is twelve issues. Providing everyone goes to their comic shops and starts a standing order (assuming they dont already have one) keeping sales up, we could go until one or both of us drop dead...
As for Ripley -- Brian wanted to set it around the time of Isolation... I think originally even make it a post Isolation Amanda story, but things were (and apparently still are) up in their regarding Isolation 2. I'd love to tell stories with Amanda to be honest. I think she's an even more complex character than Ellen Ripley is, but what Brian's seeding with her involvement so far (at least as far as I can recall, the story may change a little as it grows) is more through her past interactions with Zula. There's a sort of crossing of paths here and there.