Are there specific NAS requirements for streaming?

I am planning on getting a Cambridge Audio streamer and plan to store my music on a NAS. Reading on the Roon website (which I do not plan to use), I see there are recommendations regarding processors, memory and at least a SSD for the Roon server to reside on. If I want to use Apple Music and Airplay with controls via an iPad or iPhone, are there specific NAS requirements?  I see the current Synology and QNAP NAS units are recognized as good options. I have a old Drobo FS that I can use but don’t know if this would be optimal. This would save money but. I noticed when I used it for storing photos for my Lightroom processing , it was quite slow. 
I use a qnap in one home, and a Synology in another. I've had zero problems. I'd give the edge to the qnap in terms of ease of use, but they both make it incredibly easy to install Plex or Minimserver music server software as "apps" and then with a control point on a phone or iPad, or even the CA app, you are ready to roll. 

As it happens, I use a CA streamer as well. Settled on BubbleUPnP as a control point, with Minimserver on the NAS. This requires *very* little CPU time from the NAS. Both units are about four years old and going strong. Bubble integrates Qobuz and Tidal as well as Chromecast endpoints (in my kitchen and bedroom) so, like Roon, it puts everything in one place. 

Roon is much more CPU intensive. But I think a newer QNap would still be fine. Ask them, they have good support.
Thanks. In regards to using an external HD, I just transferred my iTunes library so the library would not take too much space on my internal drive of my Mac mini. Currently the computer directly feeds into my DAC which then feeds into my pre-amp.

In planning to use a NAS connected to my home network (as a source for multi room music), would I just relocate my iTunes library to the NAS or would just transfer files to the NAS located in a single “music” folder? (And let whatever software that the network player uses to retrieve the music)  

Seeing the Cambridge Audio network player demonstrated at a local dealer, it was not directly wired into their network but was receiving source music via WiFi. They controlled the music via an iPad, either streaming locally stored music from what I assumed was a NAS and also via internet via Apple Music for music that was unavailable locally. 

Forgive my my basic questions but I am completely new to the streaming environment, either with a local or internet source. 
Forgive me for chiming in, but I also about to acquire a CA streamer and I am probably more ignorant than the OP.

Is it not a plug and play device for streaming internet radio stations that mimic FM broadcasts? Or does the NAS just give you additional  options for services, like roon or other pay as you go apps,?

Thanks, sorry for the intrusion8-/
Hmm.  If you are keeping the Mac mini in the chain, that, of course will work fine.  Plug it's USB out into the CA and you are good to go. As long as the Mac can see the NAS, you are fine. It should recognize the CA.  Macs are good that way.

If you want to take the Mac Mini out of the audio chain and use the NAS you would be better off running a music server program.  I don't think the Cambridge can browse the network and read drives - it can only do that if the music drive is connected by USB.  But that's an option. Get a small portable SSD drive and copy your music onto it.  Plug into the CA USB port.  Cheaper than a NAS.

HOWEVER, a music server setup on a NAS makes it far, far easier to browse your collection.  Using only a USB drive you have to navigate your directory structure and choose files. It won't play albums in sequence, do gapless, or any of that fun stuff that makes it easy.  If you are a classical buff, get Minimserver and tag your collection. If not, just use Plex, or Emby, they make it easy for all the other genres, supplementing the metadata from the web.  Both come with a Qnap or Synology, and take five minutes to set up.  Then the CA app on your iphone will see your music collection and let you browse it by album/genre, etc.

@recluse- The CA app has built-in capabilities for streaming radio - you can browse by genre, resolution, country, etc., and save your favorite stations to a preset.

The CXN is a *very* versatile streamer.  You will be able to do most anything you want, especially now that they also have built-in Chromecast, which will allow you to play to the CA directly from the Tidal or Qobuz app. Spotify will see the CA natively.  There are other versatile streamers, but they are either more PC-geeky (Raspberry Pi implementations) or overpriced high-end that isn't likely to sound any different to you.  This is not the place to spend the bulk of your hifi money, IMO.

Finally - wifi.  I prefer to run with ethernet to the CA streamer.  I have a great Ubiquiti wifi setup, with huge bandwidth, but there can still be dropouts and gaps.  There's nothing like the solidity of a wired connection.  The control point can be over wifi, since that is just passing commands and file locations, but the path from the stored music files to the CA streamer is better wired, IMO.
Regarding Roon core on a NAS. I just installed it on an old Synology 1813+, Intel Atom dual core 2.13GHz processor with 2GB of RAM
It runs fine, so long as you don’t want to do any heavy upsampling, it even runs well using some eq settings.
Its an old 2013 NAS I use as an off-site backup, color me happily surprised.
It’s setup with KEFLS50w, and as a test a Rasberry pi with an Allo digione sig HAT, into a RME ADI-2 DAC. Works great