Ethernet Cards in OS X

[Pastor Mac]

I'm looking to make my Sawtooth my home gateway to replace a Win2k Pro 
machine.  Even though I keep Windows patched and have Zone Alarm Pro as 
a firewall, I'm increasingly uncomfortable with Windows' robustness 
(yeah, I know) even as a home based router/gateway.  I had to buy a 
Windows box a few years ago when I had duplex satellite internet 
service (don't get me started on the nightmare of satellite internet) 
but now that I am happily on cable, the ZAP firewall log is *loaded* 
with intrusion attempts.  So, either the Windows box becomes a Linux 
router (a task in itself) or I can add a card to the Sawtooth and share 
the connection.  I'm scrounging for ethernet cards--any particular 
chipset that OSX recognizes immediately or brand?