Auto-generated dropdown in custom field

Hi, I've been playing around with the CustomPress plugin and I'm having a hard time figuring out how to do what I need to do.

I need to create a custom post type, let's call it "Providers". Now, on another post type, in the add/edit post admin area, I need to have an automatically generated drop down menu of all of the published "Providers", where I can select which provider this new post is associated with.

Then, when viewing a "Provider" post in the site's frontend, I need a way to display all of the posts that are associated with the current provider.

I know this sounds a lot like Wordpress' post author facility, but I can't go creating a new Wordpress user for every provider that I define.

I'm fairly new to Wordpress custom post types and taxonomies, so I'm not sure what the best way to do this would be. Can someone point me in the right direction?