[K12OSN] introduction and PXES question

[Eric Neiwert]

Greetings
Having been a Macintosh administrator for the last 9 years of my professional career I am taking the plunge into using  Linux lab to solve some problems I have faced with our statewide testing we have here in Oregon.
This year every students will test at least twice in front of a computer as all statewide testing is done using a computer and a network connection. Over the past two years this has taken the lab away from classroom integration and turned it over to
testing. 
I needed a network solution that was inexpensive and flexible so that I can continue to teach language arts, science, math, and social studies using our computers. So I am piloting a lab for the district using the k12ltsp server.
I have been working on establishing a lab of thin client machines using a mish mash of older computers that were being surplused out by our high school. They have a variety of network cards and monitors so making a boot floppy for each one was going
to be problematic.
I have the server set up and it is working well. 

I also have been able to use the PXES boot CD for the client machines (a simple solution in that the CD image has most ethernet cards defined already) 
The only problem is that the default boot method on the PXES image doesn't find the server and I have to choose XDM to get it to find and boot from the server. (I can't just boot it up and let it run but have to intervene in the boot up of each
machine)
Has anyone used the PXES image to boot from a CD for clients of the k12ltsp server? Has anyone been successful in getting either the default method of logging in with the pxes image to work with the server or customized the image to only boot using
XDM or some other successful boot method? I have been struggling to figure out how to customize the image even though the author has provided documentation, a configuration folder, and the iso boot image on his web site. 
I may just revert to putting a boot partition on the hard drive of red hat and have it log in but would like to get this option to work for me.

Here is the web site where I got PXES from...
http://pxes.sourceforge.net/
A "how to" to configure the iso boot image...
http://pxes.sourceforge.net/howtos/Creating_a_Custom_RDP_ISO_Image.pdf
The downloads for the iso image and the config files.
http://sourceforge.net/project/showfiles.php?group_id=45684&package_id=38453&release_id=258546

Eric Neiwert
7th grade humanities
Technology Coordinator
Gordon Russell Middle School
http://russell.gresham.k12.or.us
Gresham-Barlow School District
Gresham, OR