Casparian

More PC FANS!!!!!!!!!!!!!!!

Mounting pump res on to fan bracket

You can see my pc in my signature below, but I went with the Define S, and at no time whatsoever have I regretted it. My pc is much more power hungry than the one you are proposing, and it is great for quiet watercooling (also I would HIGHLY recommend always using 280/420 rads over 360 rads. A good 280 with good 140mm fans outperforms a 360mm rad of similar quality because the area difference is rather small and 140mm fans are just that much better.)

Pump Res finish and tested!

Check out JayzTwoCents recent video on the 1800x in the Evolv, airflow isn't that great for watercooling in it.

Well, for a dead silent computer you need passive cooling. You can DIY something, have a look here:
or dampen all noise generated. like here:
Air cooling with large heat sinks and good quality slow spinning fans (Noctua) is not a bad start. The pump will allways be to loud.

No one would ever do that. Its like running the whole loop across your room.
 
*look at LinusTechTips videos*
 
Oh wait.....

If your a fan of large cases and Tempered glass, take a look at the Thermaltake 'The Tower 900'! 
 
Edit:
I have a friend with a 7700k, MSI 1080TI sea hawk EK and Maximus IX formula, with 2 480 rads full of noctua fans, its VERY quiet, can hear the pumps more than everything else!

AntVenom did that were it went to the basement.
 

The most silent water cooling can get is put it in another room

900D is definitely my top pick among those cases you mentioned. Take a look at JayzTwoCents videos

Wow that's weird, I've never been so "deep" in watercooling problems before

Yes, because the pumps can be louder than a fan spinning. Also the fans