If you want quality silent hubs how about
True Precision S2 Stealth MTB hubs?? Totally silent rotation and, the best bit, instant engagement! Only issue is possibly a little more weight than a conventional paw hub, if that matters (though the weight has been improved with the new S2 version).
If engagement doesn't bother you then Shimano is an easy, relatively cheap option but IMO a higher POE (Points Of Engagement) can be pretty helpful in slow speed riding situations and improves efficiency, especially in climbing.
Hopes from the factory are definitely loud but rebuilt with slightly different weight oil they shut up quite a bit. Similar story with Hadley, King & i9, they can be somewhat loud from the factory but can be 'fixed' with an oil change. DT's can vary from what I've heard - some are loud, some aren't. :skep:
The two pairs of Hopes on my DH bike & trail bike have been trouble free for over 3 years now. Not one issue. Yep they are loud (haven't had them rebuilt with different oil) but that lets people know i'm coming!
"How's the serenity?"
"BUZZZZZZZ"
*