If you take graphics card out of the equation for a moment (meaning to expect no added speed from it if it’s never officially supported – and provided you don’t enable manually – and if it works) other key things to think about from your original post are RAM (go for at least 12GB, 16GB if you can swing it).
And also a fast primary hard drive. Until SSDs are less $ and have more capacity, a nice compromise is a Seagate Momentus Hybrid SSD (if it’s available for the laptop you are configuring).
*** Just in case – make sure you stay away from any kind of overclocking (CPU). It’s fine for gamers but not us. Laptops like Alienware and ASUS are built for the gaming crowd. They are great for us too since they have performance components within, but you’ll need stability which overclocking can affect.