Which is the neatest way to have homepage articles and a blog?

If you specifically want to restrict your homepage articles from being accessible via their URL at http://site.com/blog/, then yes, you will need to create a separate post type for them. If, on the other hand, you don’t care whether they are accessible by their own URL, but just don’t want them to appear along with the “normal” blog posts, then you could easily hook into pre_get_posts and modify the blog query to exclude them from the default blog archive view.