Agreed, get a 4-channel. Also sorry, I must've just got offline when you PM'd me.
For Big 3 lengths, it's really a matter of doing a little measuring, but for all grounds, the shorter the better, we're talking 3 ft. max if you must. For battery ground to chassis, 1 ft is enough, for engine ground to chassis, you should be able to squeeze by with 2-2.5ft. For Alt to power. 6-7 ft will give you good wiggle room. Measure it out, add maybe half a foot to each measurement, order that much, then you should be safe.
