Comic publishing companies open to first-time writers and original ideas?

I'm an aspiring graphic novelist with a complete script and an idea for a full series. I have currently submitted to Dark Horse, but I like to have a back-up plan. Does anyone know of any comic book companies that are open to first-time writers with original ideas? Any companies willing to allow work to be submitted?Comic publishing companies open to first-time writers and original ideas?
Image is the only other one that comes to mind but they very rarely take written submissions. They rather have a writer/artist team submit fully created pages for a book.