You should go from TV to receiver. This means that any source that goes to your TV can ultimately be played back in surround sound.
If you connect a Blu Ray or Laptop to your TV via HDMI, the TV will then also pass the optical signal to the receiver.
There is no quality difference between digital optical and digital coax so long as you use a 75ohm cable (which is the spec for an analog video cable but not usually for an analog audio cable).
For my own set up, I had to buy a digital coax to optical converter as my TV digital audio output is digital coax only while my receiver is digital optical input only. My receiver receives the dolby digital surround signal just fine with 2 different types of cable and a converter in between.
Because it is digital, cable quality is only important up to a point, in this case a 75ohm video cable. I just picked up one of many old ones I had that was the shortest length required.
My only issue is that my TV outputs DD only not DTS. To get around that, I use AC3 Filter on my laptop to convert any DTS source to DD.
That is the only possible downside ie that your TV does something similar but as far as I have seen, all TV broadcasts use DD not DTS.