How does he like to carry his music.
By this I mean, is he someone that likes to carry all his music with him, or is he someone satisfied with having only a few hundred songs with him at any one time?
If he likes all his music at all times (perhaps why he used to have a classic -- they store the most), then go for another Classic.
If he's content with several hundred or a few thousand songs with him but not all his music library, I'd go with the iPod Touch. If this is a bit expensive, I'd go with the Nano, which offers similar storage capability, but is just a music player, and not a full-blown internet-capable computer.