Can This Amp Power A 50 Foot Speaker Cable Run?

I'd like to run 50-60 foot speaker cables of 12 AWG cable to a pair of 6 ohm speakers for the rear channels in my home theater.

Would 10 AWG be better?  The specifications on the amp says 6 ohms is the minimum impedance that it will play safely.  Do you see any issues with this?  Does the amp below seem to be up to this task?

Stereo Amp Specs are as follows:

Dynamic Power Output: 2 × 140 Watts at 8 ohms
Total Harmonic Distortion: 0.08 % at rated power
IM Distortion: 0.08 % at rated power
Damping Factor: 100 at 8 ohms
Input Sensitivity and Impedance: 1 V, 50 kohms
Output Level and Impedance: 1 V, 10 kohms
Rated Speaker Impedance: 6 ohms MIN
Frequency Response: 10 Hz – 100 kHz, ±1 dB
Signal-to-Noise Ratio: 110 dB (IHF A, 0.5 V input)
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Infinity Kappa 7.1 Speaker Specs are as follows:

Nominal Impedance: 6 ohms
Power Rating: 30 to 250 watts
RMS Crossover Frequencies: 500Hz, 4.5kHz
Frequency Response: 39Hz-35kHz +/-2dB
Sensitivity: 89dB 2.8V/1 meter