In order to run ROHQ, no choice but a new HTPC. I don't think a NUC has enough oompf to run HQ.
But don't buy a NAS if you go beyond the 2-disks models, they are expensive and too often underpowered.
If you have a third room available, I would suggest buy a dirt cheap refurbished off lease basic server like the Dell T30 and use it as your JR Media Server.
Those small servers are really power efficient. I do not have a Dell, but my server most often runs below 40 Watts, with 5x 5TB and an SSD. Haswell and later CPU are amazingly efficient, yet have the torque required for heavy lifting, like transcoding for tablets. And they are built for 24/7 operation.
I mentioned a third room because of noise issues. You don't want a file server in your HT or music listening area...
And in the same vein, I would suggest an HTPC should not have hard drives, just SSD, and rely on the file server for media.
Cheers !