Sorry for the late reply. For gaming, your best choice is your first link at $749.99:
Gateway 15.6" Intel Core i3-330M 2.13GHz Laptop (NV5909H) - Black
With a ATI Mobility Radeon HD 5650, one of the best laptop video card on the market, it's the perfect laptop for gaming under $1400. The processor is also quite fast for a laptop in this price range. Add the 4GB of RAM and the 640 GB HDD and you got a well pretty good computer. Just don't expect to be able to play games for too long when your computer is running on the battery.
