Help with choosing music server

I installed an ssd in my mini and boot up time is about 1/4 of what it used to be. I won't be spending 3-4 times what I paid for the mini on something that doesn't even have built in wi-fi. The Vault 2 has to be connect to the network via ethernet connection. FWIW I think the mini with Audirvana+ is pretty hard to beat especially with all the other functionality.

+1 on the Innuous Zenith 3.  Very easy to set up and use with ios app.  Works well with Roon. Great sound quality.  Internet radio. Available with 1 to 8 tb of storage, as already stated.  

+2 on the Innuos.  I went from using my mac to an Aurender and now to an Innuos.  The Innuos is by far the easiest to use and best sounding.  Using the Aurender + itunes was very time consuming just to rip 1 CD.  Insert the CD, create a folder, google search for artwork, download artwork, add artwork to created file, highlight CD songs from itunes and drag to the created file and on and on..... With the Innuos you insert the CD and it does everything for you....plus I get to use Roon now, which I love.

You rip a CD and it pretty much gets organized the same way iTunes does.

I don't like amount of scrolling you have to do to get to particular album in Itunes, but if you create "smart playlists" for each genre (like "genre IS Jazz") then Itunes displays whole page of thumbnails of all records in the genre - much easier to use.

As for the server - I use WiFi on Mac Mini to transfer data (on 5GHz band) to Airport Express, then by Toslink to Benchmark DAC3.   I keep my computer ON all day placing it in the "SLEEP" mode at night.  It wakes up instantly.  Since I'm sending data (no timing) over Wi-Fi computer (playback program, speed, amount of memory) is not important.  Same (other than conducted electrical noise) goes for Ethernet or async. USB.

The new vault 2i has both wired and wireless internet if that is a big deal to you.
Personally I stick to wired as very little chance of any dropouts while streaming.
Owned my Vault 2 for nearly 2 years and only just now getting thoughts to possibly upgrade.
But I had same thoughts last year and stuck with the Vault 2 as to replace it was going to cost a heck of a lot more than the 1k I dropped on it!