Prior to going on a trip, in order to put movies on the iPad I have to run movies through Handbrake, then sync to iTunes, then sync my iPad to iTunes. And then I'm limited to the iPad's fixed storage space.
You don't necessarily have to convert video files before putting them on iPad. Just get one of the many media player apps that play multiple file formats.
As for storage space, consider using a wifi hard drive. And I'm sure once SSD prices come down enough, we'll get wifi SSD drives.