Setup a single Mac Server. Create an image on a MacBook. Then copy the image to the server. Provide the image to the NetInstall service. Then boot your Mac in network mode. It'll ping for a server and once it finds it, it will load this image.
Depending on your network, you may be able to do 5, 10, 25 or more concurrently. Disk i/o will become a factor if your server is providing the image from a 5400rpm drive. I use a Mac Mini with a TB2 attached device to provide images. I usually do 3 at a time which seems to work fairly well. Any more and it bogs down.