Sound Card

I chose to use an external USB sound card because there is less electronic noise outside of the computer case. The sound should be a little cleaner with this than an internal sound card, but either will work. Another benefit of a USB sound card is that you can attach quite a few of these at one time to create many zones in your house. My card is the Creative Sound Blaster MP3+ . I got it for like $35 at a local retail store, but you can order it directly from creative with the previous link if you can't find one locally. Any card will do though.

Speakers

I found a good deal on some Logitech computer speakers. They are 2.1 Dolby. They have an 8" subwoofer and a couple of 3" satellites. I bought two sets of these for extra loud noise. You can use 1/8" to RCA adaptors and hook it directly into you home sound system if you'd like.