What's the best way to connect a PC to a home cinema system? I've got a shuttle XPC with optical & 5.1 analogue out (3x3.5mm) and a Teac AG-10D + 5.1 speakers. I might get a new sound card (Audigy 2Zs etc) if neccessary. Ive got the video sorted, just the sound now. What do you guys think?