G4L can create a number of images for different machines. In my building, we have 8 labs with difference configurations, so have 8 images. The images in each lab are imaged exactly the same, but that is everything is the same exactly software and everything. In my own lab, I have a program that makes some minor changes to the system based on the MAC address on the next boot up.
The college has a site license of Norton Ghost from before Norton bought the program, and at one point I had the machines automatically start at 6:30am with WOL, and they would automatically ghost the C partition from the hidden D drive, but that was using 98.
You would also run into a problem with time, since imaging over the network eats bandwidth. Doing a single machine in my case takes about 50 minutes with a 15GB image (compressed), and it increases with more machines. Doing 20 at once with a 100Mb connection takes about 6 hours. Using UDPCAST, can let me send a single image to 20 machines in about 55 minutes, but it does full load that network segment, since it uses multicast, but does greatly reduce the time.
I'd probable have to know some more details on the setup, to give a better suggestion.
You could emai me - firstname.lastname@example.org
Hope this helps, but it sounds like it will require some real planning to get the best solution.