If you own a MiniDisc recorder, you'll probably want a receiver with a digital output jack, either coaxial or optical, depending upon your MiniDisc recorder's input. If you're going to be using a powered subwoofer in your home theater setup, you'll also want a subwoofer out. That way you can easily add a more powerful outboard amplifier later, relegating your AV receiver to preamplifier status. This will allow your receiver to pass the signal from a future surround-sound format. This enables both the receiver and your speakers to perform more efficiently.
Power is the most skewed specification in home theater.
Because its only given for one frequency, not the entire range, the second spec probably means there is a significant power drop off at the frequency extremes when all five channels are in use. The bottom line is when looking at power ratings, try to get a rating that covers the full audio spectrum, not just one frequency. Like a lot of home-theater gear, receivers have a wide price range.