Powering trailer winch

So I'm going with my father and little sister on a moose hunt in October, and had a bare winch given to me today that I'd like to mount on my utility trailer. Mounting it is the easy part. The issue in dealing with is that it doesn't have any wiring, and I'm not real sure how to get power back there. So far I've got

A: buy a 30' length of heavy ish welding cable (cheaper than battery cable locally) run positive only to rear, ground somewhere on the rear of truck, or even just the trailer frame.

B: put a battery in my toolbox mounted on the tongue just for the winch, and find a way to charge the battery off the parking lights without frying my bcm. We have a hot patch trailer at work that charges off the truck to run the burners , so i know it's possible just not sure it's feasible.

Also, if anyone knows what's necessary to make an atv winch function so i know what to buy and how to install it all together (I've done plenty of wiring, just not confident with this one)
Almost thinking about buying a new one at tractor supply since the wiring kits on amazon ate half the cost of the winch itself and i still need cable