I have used the following site: http://pxeknife.erebor.org/
as a basis & added/reworked menus for PXE bootup of various images.I use qemu emulation to test my images before adding them into the menu listing.
Download the PXE menu script.
Though I am not using it in conjunction wtih K12xx, you could easily adapt it.
Burroughs, Henry wrote: