Can I purchase a Sky HD Box from another/3rd party manufacturer?
You pretty much have to buy an official Sky HD box in order to be able to sucessfully receive their HD service, although in fairness the cost is currently only around 49, including installation and set up. As an alternative you can pick up a second-hand Sky HD box, from eBay for example, but you will have to arrage/carry out the installation and set it up correctly yourself. Technically you will need a multiple LNB with at least 2 outputs in order to watch/record more than one channel at a time. Taking this unoffical route is more perilous, as you will need to call Sky to have them authenticate your new box and viewing card, and this assumes they are prepared to accept you’re not doing anything you shouldn’t. They would need to be convinced that your viewing card is not being moved between multiple decoder boxes repeatedly.