Will it fit (specifix RAM on iMac)? Cheers!

I have an iMac 27" mid 2010 with Intel i7 2.93Ghz and MacOS 10.9. For now it have 8GB stock 4x2GB RAM but I want install at least 16GB+ RAM.

All official documents and data-sheets (especially Intel's chipset data-sheet) tells me that I can't install more than 16GB RAM with 4x4GB plates. But experience of all other users tell me that I can successfully install up to 32GB RAM with help of 8GB plates. Who is right?

I want to install 2x8GB of this Kingston: KVR1333D3S9/8G with 2x2GB of stock memory and get 20GB in total (smth like this this).

So, will it fit and work?
Here is your model on EveryMac.com, according to them it will support a maximum of 32 GB of system RAM.  

The mid-2010 iMacs support 1333 MHz PC3-10600 DDR3 SO-DIMMs with 204-pin.  Crucial mirrors this statement.

According to the datasheet you linked, the Kingston RAM is 667MHz.  I believe when it comes to RAM, the machine simply lowers the frequency to a consistent level in order for the RAM to be compatible across the entire computer.