Scripts for setting DNS search suffix and such..

Since network interfaces don't exist until the image runs the first time I was wondering if anyone could share how they configure things like DNS suffix search order? Or really anything else. I have a little tweaks StartupItem that I'm injecting to try and set things... just trying to save time if someone else already looked in to the different pmset things to set power stuff and how to set DNS suffixes... all that jazz... thanks in advance for any and all replies...