The settings of the laptop are connect to the region. Every region have your settings in the laptops, so it is normal in some places dont find a laptop with the i7 6820HK.
If there in your region, and if you have the money, go to the i7 6820HK.
The i7 6700HQ can work with 4 cores at 3.1 ghz, 2 cores at 3.2 ghz and one at 3.5 ghz. The base clock is 2.6 ghz.
The i7 6820hk have a base clock of 2.7 ghz. He works with 4 cores at 3.2 ghz, 2 cores at 3.4 ghz and one core at 3.6 ghz. You can note that the name of the CPU is "HK". That means that this cpu is unlocked, so you can overclock him safely to 4.0 ghz.
With the overclock, allowed by asus and gaming center, you can have a performance of a desktop cpu on a laptop.