An AppleTV might solve your problem. With the TV on, it can stream video from a Mac (and with third-party add-ons, can do DVD images and other non-Apple video formats). With the TV off, it has a perfectly reasonable SP/DIF optical output which can drive your stereo. You can control it remotely from an iPhone/iPod Touch with Apple's "Remote" application, which is very well done, or you can stream to it from a Mac or PC laptop using Apple's "AirTunes".