You can create a custom template and assign that to both your homepage as well as that specific post. Templates are normally for the page post type, but you can add
* Template Post Type: post, page
to the comment at the top of the template file to make this available for posts as well.
You can then use WordPress functions such as is_front_page() to check to see if you are on your homepage or just a post page – this would allow you to load different widget areas / sidebars.