Why not go straight 20ga single strand sivler wire with Teflon jacket? Forty feet of wire will run about $80. Terminate with your favotite connector and be done with it. Also, keep +/- wires spaced, since air is an almost ideal dielectric.20ga wire will handle about 1.2A of current. Your 45 running 2 watts into 8 ohms will push about 0.5A, even at 4 ohms the current load is only 0.7A. You have plenty of margin.
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