video scaler/doubler question

I know very little about video and have what may be a really dumb question. We recently bought a bought a Samsung 42" rear projector tv. I was wondering if there is anything I can use to enhance the video quality on standard Directv signals. The tv does not have a VGA input and I was also wondering if buying something like a DVDO and then a cable that converts VGA to component video would work. Would the VGA to component video cable kinda cancel out everything that a scaler/doubler might do??