Hi Mark,
In the kickstart you have the option to set a static IP on the networking options line. (see below) There are lots of kickstart examples on the web.
# network info
network --bootproto=static --device=vmnic0 --ip=192.168.100.1 --netmask=255.255.255.0 --gateway=192.168.100.254 --vlanid=69 --hostname=someESXhost.domain --nameserver=192.168.100.1 --addvmportgroup=0