new laptop owner asus g75 help please

how is everyone doing , i am in need of a laptop soon , as my old desktop is junk..
first off is i no there is more power in a desktop but i want a laptop for traveling, as battlefield 4
is coming out , i decided i wanted a gaming laptop after tons of research i narrowed it down to the g75.
so with that in mind , i found his

ASUS ROG G75VW 3rd Gen i7, 16GB Ram, 1TB HD, GeForce 660M - Dartmouth Computers For Sale - Kijiji Dartmouth Canada.


here are my questions
1)will i be ok with the 660 gtx video card or should i find one with with the 670?
2)is there a different laptop anyone would recommend ?
3)will this play battle field 4 on the high settings?
4)what is this worth used ?
5)is it safe to be a used laptop off kijiji if i can save 700$?

and yes i am going to see if i can get it cheaper then his asking price


also found this but with only 12gb of ram

http://halifax.kijiji.ca/c-buy-and-sell-computers-ASUS-REPUBLIC-OF-GAMERS-LAPTOP-W0QQAdIdZ515105293

 

1) The 660 is the same speed as the 560M and is the weakest x60 series GPU we have had for a bit, the 670M is much stronger.
2) Head over to the what notebook should I buy but you could look out for a second hand MSI barebone (16F3) as they are also upgradable.
3) Not enjoyably.
4) Can't see the detailed specs any more.
5) Without a warranty you could not really call it safe to buy second hand you have to know what to look out for.