Gallery design question

I want to design gallery showing images I have retouched. Ideally, I'd like to have two columns of thumbnails down the left side (before and after, side by side). These would display individually in the space on the right.

Can this sort of configuration be done in Gallery2? Pointers to any similar, existing galleries would also be helpful. Thanks.

Footnote: I want to link to images stores someplace like Photobucket, rather than upload them to my site. I'm told that this complicates matters. I'm not a web designer, so I don't know.