Just go to a farm or ag supply store and see what they have. You need the wire, insulators, and a charger -- best the type you plug in. My insulators are just plastic stakes, kind of look like tent stakes with a hook on the end, 6" or 8" long. You screw them to the fence posts and hang the wire on the outside, so it doesn't touch the fence wire. For mine you need an indoor place to mount the charger - it's in the coop, up high. They come in different current loads or strengths -- you don't need a real powerful one to chase a fox or coyote, not like you do for cows and horses. Hopefully you will find a helpful salesperson. My larger dog touched her nose to it once and never went near it again. When installing, keep in mind that vegetation and snow will ground it out so there is no charge.
