Laptops suck for gaming. Especially for games requiring a lot of CPU power like CIV. The CPU's of most laptops are limited to low 2Ghz ranges. Then there's the issue of the harddisk. Most laptops are stuck in the 90's with 5400rpm drives. Yes they are getting SSD's too but lots are sold without.
An i7 4670k with a medium range board will do 4 - 4.5Ghz stable on all 4 cores with a medium sized cooler and cheap ram. Even if you don't overlock it will blow the laptop out of the water at a 3.4Ghz stock clock and 3.8hz turbo.
For a budget of $2,200 like someone gave above you could have a monster PC with 27" ultra HD monitor. Now compare that to the tiny, slow, hot piece of - censored - you would get as a laptop for the same money.
Hell you'll even be able to fit a decent notebook into that budget for your portable office work and have both.
Your shopping list should look something like this:
4670k
Gigabyte Z78 D3H (mobo)
Scythe Grand Kama (cooler)
8GB Corsair 1866C9 (memory)
256GB Samsung 840 EVO (SSD)
GTX770 (videocard)
700w gold certified PSU
Thats your basic PC for roughly € 800. You'll need a case, keyboard, mouse and headset for another € 150 or so. Pick a sexy 27" or 30" monitor.
Total price for being a PC badass, less than € 1500
I would love to get to know which components are most important to boost performance - obviously CPU and GPU matter - but what else ? How about multi-core / multi-threaded CPUS ?
4 cores are enough for CIV, and any game out there. If you get a 4 core CPU with hyperthreading you're better off disabling HT. You'll get less heat, more headroom and better single thread performance. Unless you're into video encoding or other true parallel workloads. Games just don't work that way.