Best way to show single.php custom post type info from a plugin

I am developing a plugin that utilizes a custom post type of listings with custom fields.

I would like to over-ride the single.php content and display a content part from within my plugin that will show the content and custom fields as a single. This plugin will be installed on various templates, so I'm not sure where or what the appropriate place to do this is.

Is it appropriate to filter the content? Thanks for the help.

Site with post loop:

When you click on a listing - I want this page to be the themes default "single.php" and insert/over ride with my info...