If any version of pdaXrom will work with it, it would be r198. People have complained that it is hard to install, but I found Debian MUCH harder (I think the Debian folks have eased it somewhat now, though).
IIRC, you have a 2GB SD, a 4GB SD, and a 64MB CF, no? You could become stck with uBoot if you don't have a card large enough to do a NAND backup (256MB) onto that is <1GB.
HTH, and sorry it's a bit rushed.