Hi,
so, finaly I have made it, a fully working pdaXrom for c3000. Btw it's not really finished yet as I still have to finish the c3000 implementation in the pdaXbuilder but I think I'll now take one week of real holidays before finishing that
The Beta can be found
Here and here are some instructions :
1) Check and decompress the pdaXrom-c3000.tar.bz2 to your CF or SD card
2) Ensure that your C3000 machine has a standard HD partitioning (e.g. as it was originally), booting may fail if this is not the case
3) Turn the zaurus over and flip the battery case switch to “Unlockedâ€. Remove the battery cover, and find the small reset microswitch on the left. The battery cover or the stylus can be used to press it.
4) Switch back to locked without puting back the battery cover yet as you'll need to reset again
5) Insert the CF card with the image in the root, as described above.
6) Plug in the AC power jack. The yellow charge lamp must be on indicating external power, or you will get an error message in japanese later.
7) Press the “OK†key and keep it pressed while pressing the “On/Off†button on the front side.

The Maintenance Screen will display. Choose “Update†this is item 4.
9) The next screen will ask the source, choose “CF†or "SD".
10) The next screen asks for confirmation, choose1 “Yes†this is the left button
11) now, in the pdaXrom updater menu, choose option 3 - "NAND Flash utils"
12) choose option 1 - "Resize root partition" and enter 6 (any other value may either not permit flashing or brick your Zaurus)
13) Your Zaurus will then reboot, reset it and restart from steps (5) to (10)
14) Then choose the first option 1 - "Install new ROM"
15) When it ask you if you want to format internal user flash : answer "No"
16) Choose 6 - "Install hdimage (c3000 only)" and wait as it will take a while
17) Finally go back to 3 - "NAND Flash utils" and seect 2 - "Format user Partition"
Et voilà , now you're ready, just reboot with 7 - "Reboot" and enjoy pdaXrom on your c3000
and please give feedbacks about found bugs and method you used to fix them