[REQ] Need image gallery script (Full Screen)

I need an image gallery script for my website. I can pay its price. It should look like this.

Categories:
Category A - Category B - Category C - Category D

In Category A
Other Category 1 - Other Category 2

I struggled with explaining this 2 level category system but I hope you understand. If anyone can help me, I will appreciate.

What platform are you designing on Wordpress/Drupal/Joomla/HTML? Is the multi-level gallery integrated into a map or is it for a product line?