OS X Server Configuration File

I primarily manage Mac servers these days and would like to use InstaDMG to create my base installs. I also use the Casper suite, which I use for deploying patches and applications. What I'm having a bit of difficulty wrapping my head around is how to handle the server configuration file in an automated way. I figure I'll pre-generate the file once I have the serial & MAC addresses for the new hardware, but then how to get it onto the machine? I have considered a few options, and would like to get opinions of those who know more about InstaDMG than I. Option 1: Build it into the InstaDMG workflow. This will result in a seperate base image for each server, which doesn't seem very practical, storage-wise. Option 2: Build and continually update a package that contains configuration files for all of my active servers. Include this package in the InstaDMG workflow. Option 3: Build the InstaDMG server image without a configuration file. Deploy it as a separate package to be included in a Casper configuration. Options 2 and 3 seem best to me, but I'd like to get some opinions before I start pursuing these, or perhaps another option I haven't thought of. Thanks in advance.