I will buy a fanless NUC and a techie friend will install the OS and the necessary software. I'll just stick to Roon and see how that goes.
Get the NUC8i7BEH (or i5) with the m.2 Samsung 970 (or 980) as boot drive with 16GB RAM (in case you change to Windows later). Normally for ROCK installation, you just need the smallest capacity version of m.2 SSD. But in case you change to Windows in the future, a larger one won't hurt.
NUC10 has worse GPU for Windows. NUC11 is not approved for ROCK. NUC7 and NUC6 are weaker. NUC5 cannot boot from m.2 in ROCK.
In case you want to use a LPS for the NUC, you need one with 19V at no less than 4A. Or ask Mike.