iPod Shuffle (2nd generation) bitrates supported?

[herbstech]

I have a 2nd generation 1GB iPod shuffle that is supposed to support between 8-320 Kbps AAC. Apple also states in their specs it can support other formats such as WAV and AIFF but it doesn't state which bitrate for those. I want lossless quality on there so what audio format should I use? Is there anything that is both lossless AND compressed so I can fit more music on there? For example, 1 long symphony uncompressed is about 700MB and would nearly fill my iPod with just that one CD. Losslessly compressed, I am averaging around 250MB per CD so that would be about 4 CDs worth I could carry around on my 1 GB iPod and then swap them out occasionally. If I compromise with a lower bitrate, which is the best format for this iPod? Would it be 320 Kbps AAC? Also what is Audible (formats 2, 3, and 4) that Apple claims are supported?

I would like original CD quality (or extremely close to it) on my iPod but with a reasonable amount fo storage requirement. Any suggestions?

[herbstech]

I've actually been playing around with iTunes and am fairly happy with the 256 Kbps VBR AAC option. I am able to listen to that for hours without fatigue and the extra compression over lossless WMA allows me to get more music on my iPod so that is less fussing with iTunes. I listen to mostly long symphonies so compression helps me get about 2.5 times as many on there as lossless and about 5 times as many as uncompressed.

I still haven't yet tested the 128 Kbps AAC VBR option but I will. The default for converting lossless WMA to AAC is 256 Kbps in iTunes so they must have done that for a reason (maybe so people that are used to lossless quality wont complain that 128 is the default and that they can hear a difference).