Some people have said they have had audio drop outs with coax, although you may not. Since you have to move a large piece of furniture , I just thought I would give you a heads up. I have it connected with a Wireworld glass toslink and the sound is incredible. Even many non HDTV programs are presented in Dolby Digital. I use a Cardas Digital lightning coax for music.
As far as buying a cheap Radio Shack antenna, you would have to buy an HDTV {not cheap} tuner 1st.
As far as Comcast not being able to answer questions, thats because the people you speak to on the phone are just {no disrespect} clock punchers. Most do not know the difference between HDTV and HGTV. Their is a wealth of information on www.AVSForum.com
As far as buying a cheap Radio Shack antenna, you would have to buy an HDTV {not cheap} tuner 1st.
As far as Comcast not being able to answer questions, thats because the people you speak to on the phone are just {no disrespect} clock punchers. Most do not know the difference between HDTV and HGTV. Their is a wealth of information on www.AVSForum.com