I currently have DirectTV with a standard def receiver. I would like to record various channels and I assume a TiVo system would work. Some questions and observations: 1. I see used TiVo systems for sale on ebay an various other sites. 2. Does the TiVo system replace my standard def receiver, or does it supplement my standard def receiver? 3. If it supplements my standard def receiver, what is the high level connection diagram? Cable wire -> TiVo -> DirectTV receiver -> TV -- or -- Cable wire -> DirectTV receiver -> TiVo -> TV? 4. If I was to personally purchase a TiVo system, would I have to pay some entity (such as DirectTV) for TiVo "service"? Sorry for such basic questions, but I'm (obviously) very confused and looking for direction to proceed.