Hhh, before you do anything you have to know what you want to do. If you decide to stream S/Pdif directly from computer to DAC then you have to optimize computer and playback program for best results. If you use wireless or Ethernet then computer (speed, amount of memory, HD, playback program etc.) make no difference (other than ambient noise) because timing is broken by networking (you send data and not the music) and recreated on the other side. I use Airport Express as a receiver and jitter suppressing DAC to reduce imperfections of the AE clock. The third option is asynchronous USB with good USB cable (perhaps without power wires!) since it should be also immune to computer quality (or playback program), having timing stripped and recreated on the other side.
It all depends not only on the DAC, that you already might have, but also on the distance.
As for the backup - I keep two, one being outside of the house (fire theft etc). Using Time Machine is a good suggestion (I use it for the system backup) and it doesn't take long since it is incremental backup in the background.
It is better to know what you want ahead of time, unless you know and trust the person that would make all decision and setup for you (and have him available in the future).
Learning how to do it is not a chore - it is fun, at least for me.
It all depends not only on the DAC, that you already might have, but also on the distance.
As for the backup - I keep two, one being outside of the house (fire theft etc). Using Time Machine is a good suggestion (I use it for the system backup) and it doesn't take long since it is incremental backup in the background.
It is better to know what you want ahead of time, unless you know and trust the person that would make all decision and setup for you (and have him available in the future).
Learning how to do it is not a chore - it is fun, at least for me.