Is Roon Nucleus the best choice for Roon Core and as server?

I am in the market for a Roon Core and a server for my stored music Including high res, cd quality and some old MP3 I cannot find elsewhere. Some servers I have looked at suggest keeping the Roon Core separate due to the heavy volume of metadata. As I don’t have that much stored music, I would prefer to do these two functions in one unit and spend more on the streamer and the DAC. Is Nucleus by Roon the best choice? I see an RS9 being advertised but can’t find any information in it.
Hard to say what's best but the Nucleus would work.  How many GB's of music do you have and what's your budget? 
I have been using a Roon Nucleus as a server/streamer since November and am very happy with it. It has a bay where you can install an SSD or HDD.  I'd go with an SSD.  You can also just hook up an external storage device via USB.  Connect it via ethernet cable to your network and connect up your DAC of choice via USB (or for that matter via HDMI should you have that option) and away you go.  I have mine hooked up to a Chord Qutest via Curious USB Cable and am very happy with that arrangement.