If I were to handle this type of issue on one of my own sites I'd use a directory script (sans the submission part of it, easy to leave out of the template) and populate it with all the dealers of your product categorized and subcategorized geographically. You might consider letting the dealers themselves write their own descriptions, since they'll all probably have differences in approach as well as the differences that may crop up regionally/culturally. As long as there are a variety of search terms used that people would use to find your product, then this will probably do the job quite nicely.
The one thing you can't control is whether one of your dealers (or their competitors) might beat you out in the returns.
But if you follow a lot of the advice on this forum you should be able to help your own rankings as well as those of your dealers.
I've skinned the
directory script from Tolranet a couple times and found it very nice to work with. Since one of the projects I did using that script was a site that included a similar mix of places with and without websites, I know that script will do what you wish. Paul is one of the members here on the forum as well.
If I'm remembering correctly, this script offers an RSS feed, which will help your site in the search engines.