A couple of questions:
- what are the other speakers?
- do they support bi-wiring?
- what equipment do you have? (Merely to help justify the cost- hi$=yes, midlevel$=maybe, entry$= probably better uses of the cash.)
- does the quality of this equipment warrant it, and will it enhance the sound?
- does this WAF support this? (Wife Acceptance Factor)

Without this, and probably with this, I would do this for the main speakers, and not for the surrounds. The cable gauge you are looking at (10, or 12) is very heavy. This is typically were owners of hi fi systems aim.
In my systems, 12 is the minimum and perfoms nicely.

Regards,

BBIBH