You can get bulk battery cable in anything from 8GA all the way down to 2/0
and any connectors you need at
www.delcity.net
I've been a customer of theirs for 10 years and they have never disappointed me.
I looked at Home Depot and while they do offer that size of cable, the strands are larger and it is much harder to bend along the contours.
BTW: They also have great prices on stainless steel band clamps (fuel injection clamps)
Doug