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-/