Best place to make proxies

I’m wanting to make a Nightmare on Elm Street themed commander deck where I modify the art/images on MTG cards with scenes from various Nightmare on Elm Street Films.

Does anyone know where I can take images of existing MTG cards and just edit the image inside easily with an image of my choice so I could make the proxies and then print them?

For example if I wanted to modify Pick Your Poison from MKM with an image of Freddy Krueger with his needle fingers, where/what would be a good way to do that edit?