24,000 songs is a HELL of alot of music. To put this into perspective, I have 2000 items on my 60GB Ipod Video and it takes up 10 G. Now granted out of the 2000, probably 50 are either video's or actual movies I have burnt down to it.
Problem is, even if you only put half of your songs on there, 30GB wont even come close to holding that many, only 7,500 songs. The 60GB will only give you 15,000.
But hell, if my 2000 songs would take 6 days to play, imagine 24,000, you'd never get thru them.