finding a wireless provider

I’m in a very remote area and need help deciding on the correct isp wireless provider. When it comes to cell phones, Verizon is almost useless out here, and Sprint isn’t a lot better, BUT Net 10 and Cingulair seem to get a good signal, go figure?
Does anyone have a clue how to decide on how to decide what to do as far a computer service? My phone wires are so old I connect at roughly 19,000K and they have no plans in the near future to rewire so I’m pretty well stuck in that department.