I would recommend staying away from laptops. A desktop will cost you less and give you better overall quality. Even if the hardware is great in the laptop features like keeping it cool efficiently can be costly. You can have some of the best parts in a laptop, but they might not work at 100% effectiveness.

If your mind is made up on it having to be a laptop, most laptops around 700-1000USD should be able to handle this game pretty well.

In short, you will probably be sacrificing a lot of quality for convenience if you go with a laptop.