File tree and preview with thumbnails?

Hi,

we are looking for a download / upload Manager plugin for a customer.
The customer only wants to display images on the download page, sorted in categories and allow specific user roles the upload into a category.

Due to the number of images, a tree like navigation would be nice.
As far as i can see, the preview with Thumbnails is only available in the "Preview Theme" correct?
We need a Tree-Navigation like in the "Default Theme" and preview of the images like in the "Preview Theme".
Is this doable?


Kind regards
Florian