Audioquest gets a good number of its offerings right and done well, HOWEVER, as I have been involved in computer networking for more than 35+ years building out and designing enterprise Wide and Local Area networks across continents and countries, I can tell you that what is being advertised with respect to ethernet cables really makes my flesh crawl.
As commented previously, real-time latency issues an ongoing concern, but for the purposes of data transfer and retrieving files off of a server and/or a NAS. There's not much more to build upon. Gigabit ethernet should be more than fast enough in the home for hifi enthusiasts.
Back to the Mac Mini with USB DACs. Most if not all DACs should work with the hardware, the Mac Mini, there may be issues with Apple OS X's core drivers and the versions of the Operating System. Having used Mac Minis with in my hifi system, I recommend the following:
1, buy second hand Mac Mini, if you can make it a late 2012 model, as they are the most user configurable and support USB 3.0 if you have a large library and are planning moving files back and forth on the computer directly, otherwise a mid year 2011 should be fine, I would not get an older Mac than that.
2, the safest version of OS X which should work with ALL USB DACs is Yosemite, which is two versions back from the current Sierra. Apple has made adjustments and changes to its Core Music Drivers and Library which will render some DACs unidentifiable by the operating system.
3, as for software on the Mac, I am partial to Audirvana Plus software written and developed by Daniel Plisson of France. You can run headless and operate remotely via your phone or a tablet. I prefer not to, and i connect my Mac Mini via HDMI to my 55" television screen, using a wireless keyboard and trackball to navigate. as I have 10+ TB of files, I find it much easier to navigate such wide expanses
best of luck