[...]
I'm not sure if this is totally what you're looking for but I hope it helps.
This
page http://wiki.centos.org/TipsAndTricks/KickStart should be helpful as well. In
the Use a specific network interface for kickstart, quoted "A second method is using
ksdevice=link. In this case anaconda will use the first interface it finds that has a
active link." so you may wish to try that too.
HTH
-- Zack