By separating them by categories, you could use this method. The FAQ is for cMap, but it will work with any of the premium templates that have a category drop down. Others have used this method with great success. The only item I can think of that might be an issue, if you would to use the Search widget that comes with the Widget Pack, it would return results from the entire directory unless you set the directory home page to one of the pages where you’ve limited the directory to specific root parent categories.
I hope this makes sense and helps!