Trying to setup new system for digital. Line Magnetic and Double impact speakers

I am building a new system for new house and have ordered a line magnetic 508 tube amp and am ordering the Tekton double impacts.I was wanting to start by playing digital and need some help. I know I am going to need a DAC and having been looking at the Auralic Vega and Ayre Codex but I M confused on the best way to use it? We have a lot of cds and music downloaded from I tunes which from my understanding is low quality.Is it possible to use old cds and iTunes files along with downloading high quality files moving forward I assume we would need a streamer? Music server? Any help would be appreciated want to make sure we get the correct equipment the first time.
Thanks