My client would like to have the following:
1. The site currently uses the rotating banner function. All files for the rotation are in the images/header directory
2. Different sets of images for different pages.

Is there a way to create multiple galleries for this effect?

Look for a plugin like 'dynamic headers' or 'Nero slider' or any of the other plugins out there and see which meets your needs

Thanks for your reply!

It seems to me that the Atahualpa theme tries to do pretty much everything. I am concerned about compatibility issues with replacing its header with the functionality of another plugin.

If you find a header plugin that works, use it.