"Would I get better picture if I got a Monitor/Tuner, Video card with Tuner, or Media Center?"

All the units I've seen look about equal for NTSC "analog" channels.

"I have a Sony 32"HS510 (Digital & HDTV ready with DVI) but sony said it would NOT work."

You may find ZERO help to obtain and connect DVI from a video card to the Sony. There are two problems.

1. No one knows this area well (even "Sony" people)
2. Just try to find out which DVI you have!

Bob