What gauge wire.....
Doug you are not talking about wiring a 500 ft tall rocket ship here, so the difference in wire cost is minimal. I would run no 14 if you have the room, 16 ga would be big enough.
"Opinions vary" as to charts: Between 5--7.5 A draw, no16 will be less than 2% drop in 7.7--11.5 ft of wire. Note that this is total wire, as in a boat which does not use a "frame" ground.