You are right about the GPU, the GV-N105TOC-4GD is also 0db at idle, thanks.
With reference to what Steve said, maybe you overlooked the sentence «It's another un-reviewed card
As a sound-wise safety measure, it may be better to look to already reviewed cards, the quietest likely being the MSI Gaming X and the ASUS Strix
at the moment.
If they are more expensive than the Gigabytes, you may think to further downgrade the GPU, from a 4GB 1050 to a 2GB 1050
: given that you don't use it for gaming at high resolution, but as an HTPC card, it should be a well comfortable trade off.
Downgrading to a 2GB card, you may also think to re-invest that possible savings in more RAM (you have just 2 DIMMs, so getting 16Go of RAM may be worthwhile for some applications, like photo or video editing), or perhaps in a larger SSD (750GB or 1TB).
What CPU cooler should I get then?
He just mistook the cooler: the Shadow
Rock Slim is a good pick
, as well as the other three I mentioned earlier in the thread.
For an oc'ed Core i5 like the 6600K, IMHO those four coolers are still good, as this CPU is about 10°C cooler on load than an oc'ed Core i7 (which would require a beefier cooler, like the Ninja 4 or the Thermalright Macho, IMHO).