Agree in principal moving away from the NAS, not a fan of running any software on a NAS other than those related to its core purpose (i.e. network drives, etc.)
For the server, i would not use a plain vanilla desktop with FANs nor a laptop. I would use a headless miniITX size board/chassis so you can support USB boards (like my JCAT) that the NUC doesn’t support. I felt that this was paramount as I had a NUC prior to this and wasn’t happy with the USB output, even though it was fanless.
I use Audirvana core (Studio) running on my fanless PC and the ipad app to control it.