Originally Posted by '88 E-350

The connectors needed will depend on the amperage draw of the winch. The wire gauge needed will depend on the amperage draw and the length of the wire. The smallest winch I know of is 2,000lb which will use about 10 amps with no load and up around 100amps at full load. Check your winch's specs and buy the wire and connectors that are appropriate. There are wire gauge charts available online that will tell you what gauge to use for different lengths and amperage. There are different charts based on the permissible voltage loss you want to be in. The more loss your winch sees the weaker it'll be and the harder and hotter the motor will run. To be clear, just because the winch comes with 6 ga. wire leads doesn't mean that 6ga. wire is appropriate to use if you're running wires from the battery to the back bumper of your truck.

If I wanted to run a 2k lb. winch at the rear with minimum size wire that *should* be adequate I'd probably add a 6ga. wire from the stock ground cable on the engine to the frame somewhere nearby, another 6ga. wire from the rear bumper or frame to the winch connector, and a 4 ga. wire from the starter motor's power lug to the winch connector at the rear. This is just a quick guess off the top of my head, do consult a wire chart and your winch specs. I'm assuming there isn't already a heavy gauge wire ground lead to the frame, I've never paid attention, but I'm guessing there isn't because it shouldn't be needed in a stock truck. If there already is one then the additional ground to the frame isn't needed, but if the stock ground is weak it could get overloaded and/or burnt up from the winch's additional load and if that happens there could be a lot of damage to other stuff.

Originally Posted by AuF250

Those plugs are what we call Anderson plugs in Australia. Not sure what the rest of the world cause them.
Extremely common here. Use them on trailers, caravans, 12v extension cables , winches and more.
The ones you posted a pic of look like the 50 amp versions . There are bigger 100 amp and 200 amp versions too.
In saying that these plugs are more so governed by the wire size they can take as the connector itself is pretty damn beefy. One on my 5th wheeler connecting back to the trucks 3rd battery is the 50 amp size. Probably has a bit more than that running through it at times depending on load.
We get all different brands here . Some do vary in quality of the plastic and the internal spring plate thing that holds the connector in the housing but most are about the same. They all fit into each other as long as they are the same size (rating)