Skier Collage

I am trying to make a poster for my significant other that includes all of his collegiate ski racing photos as a graduation present. I do not want this to be square photo by square photo but blended cut outs of him racing and other photos from his team experience. Looking for a 20 by 16 inch poster. I have tried my best but simply do not have the skill on photoshop. I do not know how to blend photos or how to make sure the quality will be clear enough to print. I have included an idea of what I was trying to make, but the photos are not blended at all, and the cut outs are horrible.