point the first:

each box is mathed to the card, so you need to phone sky and tell them to match the card you have to the box you have
this will mean you will have to tell them what box you have
this means they will find out you have a hd box
this means they will charge you for teh hd service
the hd box has th channels unlocked already so you can watch them with any card you have in the box regardless of it it's been matched or not, but without a matched box you only get about 20 channels

point the second:

get one if these and you can run 4 hdmi cables to the back and then one to the telly, and the fact that it's fully 1080p ready and able means that the length of cable won't make that much of a difference