Laptop gpu are very weak and expensive. A 780 m performs similar to a gtx 650 ti boost , while it is 3 to 4 times expensive than gtx 650 ti boost . You wont be able to max watch dogs out with that gpu. You need a desktop for that. Why do you need an i7 while you could get a i5 with better clock rates and cheap rates. Is wasting money that important. You dont require 12 gb ram for watch dogs , 6 gb is sufficient for it. Your laptop performs similar to a 600$- 700$ desktop.
If portability is that important, than forget games.
You cannot control the heat in laptops . That is there weakest point. In a desktop you could go more than 5 Ghz with a good cooler.