How to convert wordpress into digital asset management system

Hey,

I’ve been banging my head over this for a over a year now. Have tried many of the asset management systems out there but they are either to complex to set up, to use or downright unusable.

I work for an ad agency and need to implement a system to organize all the digital assets, this means psd’s (lots and lots of psds).
I’m looking for something with proper organization, folder level would be ideal and one which would be able to generate thumbnails of the uploaded psds amongst other assets. thumbnail generation is a must otherwise the system would be useless to us.

Please help!