The feature of the gallery should:
• Highly customizable
• Show all picture  format & video, flash, (integration of sound with the gallery will be great)
• Easy to manage lot of images/movies etc (batch upload) & possibility of categorize and reshuffle the organisation of multiple categories fast
• Ability to customize the access in the frontend— Ex: Thumbnails or directory tree
• Stand alone Mac & Window organizer apps for clients with ftp upload will be great.

Do you think I can integrate in a special HTML module something like Showit at http://www.showitfast.com/

Any suggestion?

Thanks in advance...

wouldn't exactly fit your requirements but close and its free. try expose.

You can use Joomla's copy module function to duplicate the module, and change the xml field for each instance.

Thanks to SlideShowPro for Joomla (soon to be replaced by EasySSP for Joomla!), installation is really not difficult.

There are now two versions of SlideShowPro: one for Flash and one for Lightroom.

I tried them all until I ran into this free app, and never looked back.  I needed lots of categories with sub categories.  I think it supports the formats you list (including video).  Can be customized and skinned etc.

Link is here: http://phpwebgallery.net/?lang=en

I use it here:  http://www.stevencherry.com

Click "Portfolio."

Not at all, I will ask for more. And we want it free!

I use Expose and SSP

Expose
Very sleek.  Supports video & images.  It looks easy.

SSP
It is more of a gallery for portfolios and of course a slideshow view.  With that said....

I LOOVE ssp.  I own ssp + ssp director.  You will probably need both to do what you want.  ssp director highly uses ajax.  You can drag and drop images to organize with ajax.  1 button activate/deactivate albums with ajax.  SSP color and looks is highly customizable especially if you know Actionscript.  Just go to their website and read their PDF's documentations.
Drawbacks:  It is a flash slideshow, so looking at tons of images at once isn't too pleasing.  Not really for multiple client control.  If you want the client to have some control you are better of buying multiple copies of director.  SSP directory does have user groups, but it is not good at all.  There is only editor, publisher, admin ( or something like that) you can give a person permission to edit images and upload, but it will be for all galleries.  You cant limit which galleries they have permission for.Director has 1 license for 1 domain

   On the upside the new Director coming out will support API which opens tons of possibilities.  Even looking at images without using the flash slideshow.  Slideshow pro alone without director is alright, but your clients might not like it.  You have to manually edit the XML file, and get get messy if you have many galleries and images.

Here is an example how customizable it is IF you know flash http://www.lakecrackenback.com.au/
Heres an example if the new api in Director(beta4) http://www.italyapartments.it/admins/director_api_demo/

END: SSP is more for your own gallery rather then clients.

Which way do you edit SSP settings? with adobe flash, or standalone version?

Upload your swf anywhere convenient in your server. Go to modules, then click on New and create a custom module. then click on Embed media link and put the link to your SWF.

To use director open the .fla and set the ssp setting called xml to 'director' instead of images.xml

To access your director its http://xxx.com/directorpath  You can't embed director into joomla if that is what your saying.