Need advice on music management software

[Konstantin Svist]

Hi all,

I have a music collection that's being merged from several
computers/devices onto a single one (which doubles as a media
center/HTPC). Problem is, I'd like to merge the duplicate files (and
there are plenty) but still need to be able to sync between this central
system and the other computers (all running Fedora, btw).

User 1 has a laptop with Amarok and syncs her music to an iPod (listens
on both laptop and iPod)
User 2 also uses Amarok, but no external devices
User 3 uses a car mp3 player only (wirelessly synced to her laptop using
special software...)
Everyone wants all the music on the HTPC, though everyone will keep a
copy of their own subsection of the collection on their own devices.
Nobody expects to sync to the HTPC from anything other than laptops,
though iPod integration would be a bonus.

Would be nice to listen to music from HTPC, and upon hearing a song I
like to quickly mark it to send it to my laptop at the next sync :)

Crazy setup, I know
Any suggestions?