Go look at Malibal laptops, they offer way better prices and no proprietary garbage. Alienware is a rip-off!
The 560M GPU is total crap has only 192-bit bandwidth, opt for the 485M or 580M if you have the money, though the 580M offers only 20% more performance than the 485M at 50% more cost.
It is definitely worth it to go witht the bigger L2 cache, hence an i7.
What RAM is concerned, the more the better, and 4GB right now is nothing!
Good luck and again, stay away from Alienware!
Edit: I don't want to sound like a Malilbal rep., so here are a few more resellers: Xoticpc, Originpc (Ex- Alienware execs)... I bought a laptop for work from Malibal and they are hands down the best when it comes to service.