So it needs to be the exact same ones? Like I said, anderson plugs are brilliant and almost indestructible. Forky drivers throw them all over the place. They're cheap and available in many current ratings.
By the way, don't forget to take volt drop into account when sizing your cable up if you're making long leads. I know 3m isn't massive but at 500 amps plus starting current, a few millivolts per amp per meter can soon add up and leave you with less voltage than you'd like!