I've yet to setup my own netatalk server, but it seems like netatalk would have some way to preserve the resource fork/metadata?

http://netatalk.sourceforge.net/3.0/htmldocs/upgrade.html#idp5680832

http://forums.freebsd.org/showthread.php?t=29258 (See post #2.)

Just found this guide for installing netatalk on Ubuntu. Section 2 mentions a daemon called "cnid_metad" which is suppose to handle the metadata. (Knowing what version of netatalk you're running might also help.)

Again, I'm no expert with netatalk. But if you want to try and get it working, I'll try to help.

Edit: Here's another article mentioning cnid_metad. Might come in handy.