55 Foot Speaker Cable Run

I will need a 55 foot run of speaker cable for each of my rear channels in my home theater setup. I can get 12 gauge speaker wire at Home Depot, and I know of another source for 10 gauge wire on the web for 80 cents a foot.

Will the heavier gauge be better for a run of this length?

I will run large 4 ohm speakers (Infinity Kappa 9) full range on the large setting for the rear surround. They will be powered by amps that are rated at 900 wpc at 4 ohms (Carver Silver 9t monoblocs). Banana plugs on all terminations.

Processor will be a Sunfire Theater Grand II.

thanks....mitch