How to spec a Raspberry Pi

I’m about to start a R Pi project. Along the way, I hope all about Pi audio computing but at the moment, I know nothing. This leaves the problem of choosing which Pi…

The project is for the Pi is:

to direct a TIDAL or Qobuz download from PC Desktop to NAS (USB 3.0 SSHD)
to direct USB 2.0 music stream from NAS to network streamer under control of PC and network-resident audio player (Audirvana)
possible project extension: MQA decoder and DAC to output audio analogue
possible project extension: control mains power to amplifier, control source as yet undetermined

Audio streams are FLAC 24 bit 96kHz.

Software Rasbien, Voluminio, Audirvana, Tidal, Qobuz

It would appear that R Pi 4 should be good because it gives me USB3.0 for the NAS. I have no idea how to choose between the 1, 2 or 4gB versions or what size the SD card needs to be. Could anyone advise, please? And will it need a fan (ughh!) or will heat sinks do? If so, do i need to find a metal case?

Many thanks in advance.

RAM size: more is generally better, but obviously at a cost. Volumio will run fine in 1GB, but many vendors seem to be selling the 2GB for the same price as 1GB anyway. If money is not a problem, go for the 4GB.

RPi 4 and heatsinks: I don’t have access to one :wink:, but yes they do run much hotter than previous RPi versions, especially under heavy load. Volumio really shouldn’t prove too taxing, so you may be able to get away without modification (I’m sure that someone on here will likely provide more clarification on this point). Passive cooling through a heatsink, or combined heatsink/case should be sufficient without resorting to obtrusive fans.

Have fun, and let us know how you get on.