Hello. I`ve already chosen the laptop for video and 3d editing - it is Lenovo Y700-15. But, few days ago I saw message in one forum that means: "Almost it is no difference beetwen 4GB and 2GB Nvidia GTX 960m. They have almost the same work speed and etc." This information I saw in video gaming forum. And this computer was seen as gaming laptop. And now I don't know - does it has any connection with video and 3d editing? If there is no difference - computer with 2GB costs cheaper.
Well, considering AE uses a card like that for virtually NOTHING, get what you want/
However, AE demands lots of RAM (16 GB is good) and fast processors (i7). You don't have that stuff, you'll be in a world of hurt.
This ain't shoot-em-up Video Game Land, Bud... this is After Effects.