Image Gallery Suggestions?

I am looking for an image gallery to put on my site but I need the visitors to be able to select a few images (more than just 2) and “compare” these on the screen at the same time to decide which they like better.
I was considering ZenCart and using the Shopping Cart portion to do this but it doesn’t really do the images portion nicely.
Then looked at the different photo galleries offered in the Goodies section on here and nothing seems to do the comparison portion.
I am considering writing some scripts (I made a basic custom shopping cart this way previously) to handle this but then the up keep of adding images or changing the categories/albums of images becomes a nightmare and needs me to do it and not something I can assign to someone else to do.

Suggestions anyone?