Are you looking for free to air tv, or satellite internet service, unclear in your post. If you're switching to Directv, you can get sat internet with their tv service off the same dish.. Though most of what I'm reading lately says forget their internet service, I think it's called Hughes Net now. Wildblue seems to be the service that people on the forums are praising currently, That will prob change also when they oversell their satellite capacity like the other guys did.
For free to air tv, all you need is a small dish/linear lnbf on it, 33"-39" will get KU digital signals. Lot of us find old Primestar tv dishes, they're usually free from people who just want to be rid of them, and work great for fta.
Of course with a big c-band dish you can also get the c-band digital signals that are fta. The List (link at top of page) will give you an idea of what you can receive.
