I am looking for a setup for my home to play my digital music on my
stereo. I currently own an ipod, two Mac laptops and a hifi stereo
system in my livingroom. I know I could just stream via airport
express but I would like to achieve the following:
- stream the music to the stereo 
- view music on a display other than my laptop, possibly even the cover art.
- occasionally connect an ipod to this setup
- enhance my mp3's  with some sort of music decryption that outputs a better sound
 
Which devices do you recommend that achieve this (and possibly more)
for me? How would it fit into my setup?

I know of devices such as the Sonos or the Slimdevices Squeezebox but
don't quite understand how this all works in my setup and what the
benefits are.

Many Thanks,
Florian