i've gotten 2/0 welding cable (nice flexible insulation) from Battery Service (see Contacts DB). Also i recommend Magna Lugs (much better than generic lugs). Battery Service has all the cabling supplies/tools (cable, lugs, boots, heat shrink, crimper, etc.). i have a crimper you can borrow if you want. Else, they are about $150. i can bring it to the next meeting if you want.