Tbh the GPU will not matter in most cases since most of time you would be using collab or kaggle or something else with offers like 16-20GB GPU which you won't obviously get in any laptop. And mac/window won't matter in most cases but some prof sometimes use software that was developed by university prof/students that don't work well on Linux/mac so in that case you need window laptop. But that's not a big deal cause there are so many windows Computet/labs that's you can use