Natey,
If I buy a logic board, will it have to have the firmware update for OS X on it?
Well maybe the seller would know.
To confirm that boot into open firmware:
http://www.netneurotic.de/mac/openfirmware.html
"You can press alt
alt+of when you hear the boot chime and the OF console comes up."
When you're in open firmware you'll see the first line:
"Apple PowerMac2,2 4.1.9f1 BootROM built on ......"
The "4.1.9f1" is the firmware version, which is the latest update - 4.1.9.
Richard