I don't see exact models so I can't check reviews.
That out of the way my son had something like item 3 but with a pair of 4GB sticks (for performance you need both) and gamed a lot like LoL, etc.
I am going to play dota 2 on new laptop, so which one is better:
Nvidia 720m 1gb
RAM 4GB DDR3 1600MHZ
Nvidia 820m 1gb ddr3
4gb ram (idk speed)
Radeon hd 6620G