Well the iPod is going to be limited to 10gig for another while IMO.
The Nomad Jukebox 3 is available off the shelf with 20 gigs but is readily upgradable to 40gigs here.
After that there is the Archos offering and I think that is it.

Good luck with the move, I personally went throught the same thing 2 years ago moving from Ireland to the US - BIG change.