I recently purchased an infocus 4805 for my HT. Currently we only have basic cable service. To take advantage of the projector I was contemplating trying out an HDTV service. Currently we do not use cable boxes, just a straight feed into the TV. If I get an HDTV tuner and feed, will I need to put cable boxes on the rest of the TV's? Can I just add a HD tuner onto the projector and leave the rest as is?