If you rip your own you can choose any resolution you like. Most MP3s posted on
ABSM newsgroups are 256k or 320k. The reality is, most places I listen will
have enough background noise and poor acoustics such that 64 kbs would probably
work.
If you set in a foam room with a great stereo and you just groove on the music,
then you need CDs, oxygen free cables and all that stuff but when you put out
the doobie and actually go do something while you are listening to your music
you are wasting all that quality.