I think one of two options would be best:
Connecting your MacBook to existing equipment. If you already have a TV and/or home theater a few adapters and cables is all you need to turn these into a display for movies and system for sound.
A Home Theatre In a Box. These are made by various manufacturers including Philips, Sony, Panasonic and more. They contain a DVD/CD slot, built in amp and several speakers for surround sound. It will use your existing TV as a display and do the audio itself. The only downside is these devices are tuned for movies sound-wise so aren't the purest when it comes to audio.