Speed Up iTunes Sync on 192 kbps
If this is the first sync, it has to transcode everything, which naturally takes a long time. If you check your Activity Monitor you'll probably see all cores at 100%. You could buy a computer with a faster CPU... or just be patient.

The first sync used to take about a day for me with 5000 songs on an old Core 2 Duo MacBook. At least you can stop the sync and it'll resume where it left off when you get back.