1) Is HDTV possible through Broadband cable lines? 2) Can I only receive HDTV using a satellite dish? 3) If I watch standard programing on a 16x9 TV, what size will the picture be and will it harm the TV? 4) Do All letterbox or widescreen DVD's FILL UP the entire screen of a 16x9 TV? 5) My goal is to have the sharpest and largest possible image for the money (similar to a typical movie screen but naturally smaller). Should I get a 4:3 HDTV ready set that is really big i.e. 51"s OR should I get a 16x9 format?