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.

Larger gauge is better. As an alternative to two conductor Home Depot wire, if you use Canare 4S11 four conductor wire, and twist together the opposite conductors, you end up with 11 gauge wire with the benefits of starquad geometry that helps to reduce and/or eliminate EMI/RFI.
I use the HD 12 ga stuff for a 35 foot run with banana plugs in my setup with no issues.
Not sure if the extra 20 feet would create an issue.
HD cord is pretty good stuff in rejecting EMI/RFI and no need to spend more for rear surounds IMO.
Tvad's suggestion is even better and still economical.
Gotta agree with TVad. I have 4 30ft runs of the Canare 4S11 (biamped) and it works great.

The issue is resistance. Roger Russel has an excellent rule-of-thumb for required gauge/resistance in speaker cables depending upon run and load:

What are the main primary speaker cable lengths? I just added a REL B3 to my system and it came with a 35' cable. My main speakers have 10' cables. I could hear a severe timing problem with the 'bass'. Cutting the cable down to 15' corrected that. I remember years ago never exceed 50% of the cable length for whats existing or it becomes audible. I'm glad that memory cell is still alive.
The primary cable speaker lenghths are 6 feet long to the amp and 12 foot interconnects to the preamp.