Hello Newcomer - If you have the PWD6 then what you're looking at is a plasma panel - not a television per se....it has no tuner and no speakers.
Most people who buy these have a seperate tuner (in your case Sky) and a home cinema 5.1 system for sound purposes.
Each device (Sky, DVD etc) links to the screen by means of "connection boards"....these boards fit into the panel, and enable you to then connect the devices. So you can by whichever boards suit your needs....RGB Scart, Component (best for most dvd players/systems), or HDMI.
if the installer has managed to connect the Sky box then I'm fairly sure you must have a Scart board already fitted ? Check around the panel - I'd be surprised if the previous property owner removed the boards but left the screen ??!!
Check these forums tho - there are numerous places/outlets selling the boards if you need more.
As you'll also read - the PWD6 is widely regarded as a superb screen so if you need to spend a few quid to update/upgrade it, it'll be money well spent.