You won't listen to 8 GB in one trip out, most of it just sits there.
I also recomend a cheap mp3 player, one that you just stick into your computer with and drag the files you want on there onto it.
Apple says that you must use iTunes (there are some hacks to not use iTunes). You can use music that's not from ITMS, but you must import it into iTunes, but it rejects most files (mp3s are fine (for now
)). iTunes also likes crashing.
iDon't