A 'Naruto modeled after Kakashi' fanfiction could see Naruto with a changed appearance to some extent. He might start wearing his headband in a similar way to Kakashi, or even have a similar style of clothing. In terms of his ninja skills, he could master the Sharingan - like abilities in some form, perhaps a new jutsu inspired by it. His mentoring style could also change, becoming more like Kakashi's, being tough but fair with his students or comrades.