I am thinking of opening the source and target units, swapping the slave hard drive on each, copying the files directly and readjusting the master / slave jumper on the target. Disk to disk should be much faster. Even with this, though, I expect the transfer to take an entire weekend.

Yes, I would think that disk-to-disk is your fastest method. Playing "Musical Drives" will be tricky, but it sounds like you can handle it.

Don't expect it to be lightning fast, though. The IDE bus on the player isn't the quickest thing in the world. Allowing yourself a weekend for the procedure is a good idea.