I want to replace the router/modem Comcast with a high quality for streaming

Right on @mitch2

I have a Netgear C7000v2 used with Spectrum as the internet carrier.  I've had no issues with it and it covers my modest 1000 sq-ft cottage with WiFi quite well.  What I did notice though is that until I added an Uptone-Audio EtherREGEN device which regenerates the Ethernet signal to my music-server, I was unable to get streaming music to sound as good as that from the same music loaded into my music-server.  So, cleaning up the Ethernet signal is an important part of better listening in my opinion.  

1. Go with direct 1G Ethernet copper cabling wherever possible. It is infinitely more reliable, economical and has much higher bandwidth. 
 

2. Do not “power line Ethernet” products. They do not work. 
 

3. Buy off-lease enterprise grade Cisco switches, firewall and mesh wireless access points instead of TP-Link/assus/Trendnet or any other consumer brand. It will work better for much longer. 
 

4. Use major name jacks and patch cables from Leviton or Belden or Hubbel and use brand-name Cat5E or Cat6 cable instead of cheap no-name low quality cable. 

After reading this thread, I checked my actual internet speed compared to what I am paying for and found it to be only about half what it was supposed to be.  The Comcast/Xfinity website was helpful by showing that my modem is outdated, the non-Xfinity modem options that are considered current, and a link to the speed test.   I then purchased a new DOCSIS 3.1 Gigabit cable modem from the list that will hopefully provide the speed I am paying for. 

I feel lucky to have found this thread.

Starting at the Basics, I am at present purchasing electrical cable for my home which is to undergo a substantial renovation.

My electrician friend assisting with the new electrics is aware a separate earthed spur is wanted for the Audio Set Up. 

The way things are unfolding, the Audio may be reduced to a Streaming Only arrangement, FLAC files and possibly a Hired Music Service as well.

What is the best options for me in relation to having Cable concealed in the walls?

How many wire runs is required?

Any info to help plan will be great.