where they have a lot of discussion on a lot of a computer's performance for photography. They base it on Lightroom and Photoshop; if it runs these programs, it will run most anything else well. You can use a lot of that info in helping you spec out a laptop.
The laptop will have other issues, such as drive space, screen size and ability to spec out a GPU. But this site will give you a lot to think about.
FWIW, I went through a similar thought process a year or so ago - and decided that since I did most of my editing at home, I built a desktop based on the specs that I found at Puget's site. I use my 17" laptop with an older i7 for travel and "light" editing.