If you have QuickTime Pro you don't need any other converters. You could use just QT or use the option to export to iPod format in a no. of programs.
For QuickTime Pro exporting, see QuickTime Pro: DV format movies may require adjustment for iPod & also this one Creating Video for iPod Tutorial

This is also an interesting article: (a) Verifying iTunes video conversion and iPod video syncing using sample QuickTime files

& also this one: (b) iPod Higher Learning: The Next Steps which shows a couple of other programs you can export to iPod video format.