Creating, Placing and Sizing Images from PSD masters

I have 30 very big PSD files (7360 x 4912) totally about 1gb of data. They are product photography with the background removed. I need to create 3 different sized images from them 1 big with black background, 1 big with white background and another with the images on a transparent background (JPG, JPG and PNG) I also need the subject in the photo to be positioned exactly the same across the 30 images. I will supply two completed images as reference. I can send the files by WeTransfer, and need this done relatively quickly. It would probably take me a few hours to do, but I'm trying to do too many things at once.