Saying that you cant use RG-59 for satellite viewing is like saying you cant hook up your speakers with lamp cord. If it carries an electric currant it will display a picture. Use a cut up extension cord if you want.
My suggestion would be to go with the RG-6 if you are running new wire. If not then stick with whats there. Also conduct your own test and see if theres a difference in the signal.
What we should be thinking about is how one day RG-6 wont be suffeicent to carry the data we need. Hmmmmm lets see 100,000,000 homes all needing new and improved cable to watch tv. Call your stock brokers
You are welcome to use whatever cable you wish. Don't come back here and complain about poor picture and dropouts from using RG59, though.