As you are interested in becoming a new customer, I would call them and ask for prices. You may get a very good price on a new DVR and free installation, including all the hardware that you are thinking of purchasing. I don't advise buying a used unit, too many possible problems with billing. I think the HR20/21 are good units, I enjoy using them. If you have a router all you really need is an Ethernet cable, unless you want to go wireless.