1000 CDs @ 192 should fit on a 160GB
I'd say that sounds about right, space-wise.
FWIW, you might also consider first ripping as FLAC files and backing up the whole shebang on a 1TB drive, since they are relatively affordable now. This way you won't have to worry about anything with the original CDs. You can quickly create an original disc from the FLAC files, and also create a separate MP3 archives for portable use that includes iTunes/iPod.
Having a backup is always useful IME, and relatively easy to pull off.