Using a full-width hero image that can be changed in the dashboard by a user

You can set them as featured image of custom post type and then call it within the while loop for displaying all the contents of the custom post type.

<?php
    $args = array('post_type' => 'your_custom_post_type');
    query_posts( $args );

    while (have_posts()) : the_post();
     // check if the post has a Post Thumbnail assigned to it.
     if ( has_post_thumbnail() ) {
        //access feature image
        the_post_thumbnail();
    } 
    endwhile;
?>