Need some help selecting a laptop

I’m saving up to buy a new laptop soon, and I’ve basically narrowed things down to two potential units. The problem is that, since I plan on using it for quite a lot of gaming, I’m obviously interested in getting the most appropriate hardware, but I really don’t understand the pros and cons of the various graphics cards, in particular. My budget is around 2k or less, and I’m currently considering these two units:

ASUS G50v A1
ASUS G71g-A2

It’s obviously a lot of money and I want to get the most value, so given that I’m most interested in the unit’s longevity and its applications for gaming, would anyone like to recommend either of these units or something entirely different? Assuming that the specs I linked to are accurate the G71g-A2 seems really amazing, but I don’t know how 6gb RAM and a Geforce 9800 GS compare to the g50v’s 4gb of RAM and the 9700 GT.