Hi Sean,
I think you should first think of what you want to do with the photos exactly. I mean, what is the biggest resolution you need? Etc.
Then I personally find it convenient to do a resize batch in Photoshop. I suppose you know how to do a batch in Photoshop here. You could also use: File > Automation > Fit Image. There you can give Photoshop a certain width & height and will fit all images within these width & height values.
Then you could just load all images in AE. Drag them into the compostion. You can copy the animation keyframes from one of the layers to the other ones. Or just select them all and place them in the right spot.
You could if needed use the Keyframe Assistent to sequence all the layers. (Select all layers > Keyframe Assistant > Sequence Layers)
Hope this info helps! Good Luck!