Beeper

I am a technical ingenue, and know little of these formats. I have teenage children with Sony Discman players that read ATRAC disks they burn using Sonic Stage software downloaded from Sony's website. I'm buying a new stereo/CD deck for the car, and thought I would buy a Sony system that reads these ATRAC disks. But it appears that Sony's newest models (at least those available at my local Circuit City) do not play ATRAC. This year's models seems to have abandoned ATRAC for AAC (the format newly-available on Sony systems). Does this mean that the ATRAC disks my kids burn won't play on the new Sony systems? Or will Sony's later-generation players still play ATRAC? I understand that AAC is an Apple format. Does that mean that my daughter's large iTunes library can be burned onto disks and played on one of these new Sony car stereos? What options do I have for the Sonic Stage collection? Should we reburn new discs in regular MP3 format, or is there some other way to get the ATRAC disks to play on the car stereo. Any advice anyone can give would be appreciated!