Retouch & Harmonize 3 Portrait Photos

We would like to post on our website three separate photos (next to each other) of the three members of our small team. Each member's photo has been taken separately from the other and currently the three photos have different backgrounds, different brightness, etc.

Our requirement is to harmonize the three photos with common backgrounds, harmonized retouching, as well as present them in the same measurements (currently each photo has different proportions than the other two).