I have 5+ acres and would like to give my dogs the run of the place, fence is out of the question cost wise, was thinking about the fencesless buried electric fence/shock collar. I haven't messured the perimeter yet, but will need a couple thousand feet anyways. SO here is my question/s. First any recommendations on brand model, second what kind of wire can I use to bury, the ones I have seen at most come with 1000 ft and then its 50 for each additional 250ft or something like that. I have a ton of old electric fence, can I use that?