Optical or Coaxial?

Need to make a long (35' give or take) run of the digital audio signal from DVD player to surround decoder.

1) Better off coax or optical for that length? Coax makes neater finishing since I can't find optical wall plates (2 back to back females)

2) Is the DTS information also carried by the coax?

1. Coax
2. Yes
1. don't know 2. yes.
With optical you won't have a hum problem. With coax you might. (I did).
I run 22 feet and use coax the optical was less involving
i experienced no hum