Yes, I just did this with a 3c509
look in /lib/.../net there you will see all the supported network card drivers/modules.
To use one you do...
/sbin/e-smith/config set EthernetDriver1 3c509
cat <>/etc/conf.modules
options eth0 io=0x280
(You will need to use the correct io address for each adaptor)
EOF
/sbin/e-smith/signal-event console-save
check your /etc/conf.modules file and make sure it looks OK
/sbin/telinit 6