Speaker wire is fine, just get the thinner kind with the double wire (ground and power). Current flow i think depends on the type of switch you buy, they differ in how much power they can handle. I personally liek the 3 post switches, keep it neater when you run a bunch of wires to it. Theres a ground post, power post, and like an input one. I run the power from the fuse (or battery) to the power post, power wires from the appliance to the input, and the grounds to the ground post, then run a wire from the grouind post and actualy ground it. To ground it just find any type of metal (i.e. Screws; work well cause you can screw the wire around for a tight fit). The cig lighter can only handle 12V, so you cant run a bunch of things to it. You can buy an inline fuse from bestbuy and run it through ur firewall and comes out behind ur pedal (it'll be power). wire cutters and strippers work well, or you can just use ur teeth
. radioshack has speaker wires and switches, neons you can get at autozone.
sry that was kinda long but hope it helps