Personally, I'd just dump the DVD image with DVD Decryptor, and then include a copy of the latest Daemon Tools, which can emulate a DVD Drive & then mount them as a DVD drive.
If you need one for a standalone player, you can shrink it/etc and burn it off when you are over there.
But Decrypting, shrinking and gettng around copy protections for DVD could be time consuming. Dumping straight to DVD image should avoid these issues, and you can deal with it later, if you have to.
If you have plenty of time though, you can fire up ripit4me with several instances (one for each DVD Drive you have) and have DVDshrink compress & dump them to the HD either as files, or as images.
With WinXP, you can also have the removable HD partition compressed, to maximise the available space.
If you go the srink method, dump them to your main HD first & then copy them across to the portable HD, otherwise your portable will end up fragmented ... and external HD's are slow enough already