Diskless is great if your base OS image is constantly being modified/tweaked like crazy, and you wouldn't be able to accomplish the same thing by running a shel

Diskless is great if your base OS image is constantly being modified/tweaked like crazy, and you wouldn't be able to accomplish the same thing by running a shell script at boot that was pulled remotely (each node having a standard shell). The downside of going diskless is you are trading off valuable memory for the ramdisk. Memory/$ > hdd/$. Have you considered just getting cheap/small hard disks for each node, and having a central shell script that runs on all of them on boot to bring them up to task?