As a fellow user, I would and have said your options are to…
- wait until Roon lists specific models of Nuc’s as Roon supported ( my guess would be Asus)
- buy any PC or NUC and load an operating system (Linux or Windows) and then RoonServer for that OS
- buy any PC or NUC and load ROCK understanding that you are running it on unsupported hardware and the Tinkering section would be where you get questions answered.
I personally think the second option is the way to go at the moment if you need something now. Otherwise, I’d say wait as in option one. This has been discussed before and you might want to review this thread