There are different configurations you can use from what I understand (high wattage/low ohm or low wattage/high ohm), but I opted to go with something I could find locally, at a Frys as it would turn out. I bought some 4 ohm / 25 watt resistors there for just a few bucks a piece, and they worked great. They were a little tedious to get wired up correctly, but that's mostly because of my setup and how I have everything clustered together on a rack in my trunk.

This post has an attached pic of the units I purchased (the one on the left in the red package): https://www.chargerforums.com/forums...5&postcount=13

This post has a pic (4th one down in the list of attachments) of how I mounted them (i screwed to the underside of the mounting board on which all the amps and LOC were mounted on top): https://www.chargerforums.com/forums...5&postcount=24

The wiring for my resistors is a little ugly, and I keep meaning to go back and clean it up, but I just haven't done it yet....