The problem with post format icons is they are limited to names given (video, aside etc). To be honest I think they are not that useful unless you are creating a tumblr-ish blog.
A better idea would be either use categories and style per category (add icons with css). Or create your own custom taxonomy, even a post type in this case maybe. Then you can style however you like and have complete control.
If you aren’t up for that much coding you could try one of the cms plugins that provide a ui for creating custom post types and taxonomies. You would still need to create the icons and styles.