I'm looking to set up a good speaker system for my MacBook. A friend of mine (who generally knows what he's talking about when it comes to technology) has me convinced that I should go the route of "Home Theater in-a-box" such as the HT-S590 . He doesn't know much about macs though and said I probably need an external sound card that will connect between the MacBook and receiver. He also said look for a sound card "with digital output because it will sound better". Any audio experts out there have any suggestions about how I should hook up this system? (Do I need a sound card/which sound card... etc) Thanks.