I'd have to recommend tracking down an iriver H140, putting Rockbox on it, and converting all those WAV files to FLAC. You'll probably want an amp too, though. It helps a lot with improving the sound. Plus, you can upgrade the hard drive in an H140 to 80GB, which would be especially useful for lossless. My meager H120 can only be upgraded to 30GB (there are single-platter 40GB drives that would fit but they're IMPOSSIBLE to find). Rockbox doesn't work quite well enough on iPods yet to beat the H1xx for usability.
Best of luck! And yeah, those old Creative Jukeboxes were fun. You'll be shocked by how much more usable a Rockbox-enabled player is, though.
-Packgrog