I am a bit new to this so please excuse my ignorance . I have a Dish Network setup (top 150 programming, no HBO, no SHO: L.A. area) which I have had for a over a year now. I have the DISH500 with 2 Dish 3900 receivers. What I would like to do is to add Dish Network reception to 2 more rooms. I see a HD-ready 16:9 TV in the near future and would like to take advantage of that on 1 room. Some of my questions include: *Can I get any model Dish Network receiver for the 1 new room that does not require HD? Or does it need to match my 2 3900 model receivers? What other Hardware would I need for HD? *Anyone purchased used receivers from ebay before? what are the things that you need to look out for when doing this? *What other subscriptions do i need to get from DISH in order for me to get HD on 1 TV? Any other additional info. that you can provide would be great. THANKS!