Load a given single post in Custom Post Type archive (best practice?)

Hi everybody!

I have a custom post type in my site named “services” whose capability is ‘page’. The template structure that I have is:

• archive-services.php – archive template
• single-services.php – single post template
• sidebar-services.php – sidebar that lists all the posts of the ‘services’ type with wp_list_pages (it highlights the current posts)

The permalink structure for the archive is mysite.com/services/ and for the single posts mysite.com/services/post-1.

And here comes my question. I need to load a given page on mysite.com/services/ instead the archive, and this page has to be highlighted in the sidebar.

Which would be the best practive (and “cleanest”) to get this behaviour? Changing the main query/loop inside archive-services.php? Adding a template redirect in functions.php?

Thanks in advance for your help!