Cover Art for Book

I am working on the sequel to a book I have been writing and my original artist is unable to continue working on the project due to school. I am seeking a manga artist who is willing to step in and create a new cover for my second book. The story is science fiction, post-apocalyptic zombie however the cover will only contain two characters, both of which I have composite sketches for already. I have a rough idea for what I'm looking for but I am more than willing to take suggestions, a sample document with the scene in particular that the cover will be based on will be provided upon employment. I'm not looking for 100% replicas of the old characters but they need to look similar enough for it to look like a sequel. Please submit portfolios when applying, thanks!