Which laptop processor for Photoshop

A friend of mine needs to buy a new laptop and asked me for help. I know the desktop market pretty well but not much about laptops. She is a photographer and uses photoshop and other photo editing software. Her budget is $1000.

My main question is what processor should I look for? What is the best "price versus performance" laptop cpu currently? Quad-core AMD or Intel? Or is there an amazing triple core or dual core I should look into? Point me in the right direction please.

Other than the CPU, I am planning on the following specs for her:
Windows 7 64bit
4GB of RAM
Minimum of 500GB HDD
~17 inch screen