You might want to take a look at JAMF's NetBoot/SUS server here:
This product will let you spin up a VM based on Ubuntu that you can use to set up NetBoot on non Apple hardware. Its not quite as robust as Apple's version under OS X Server, but it does the job for many people.
We still use Mac OSX server (on Mini's) for NetBoot, Casper (DP's & JSS) & ASUS.
(As well as NTP).
Cheap at £1k with AppleCare, cheaper than carving 500GB from a left hand node on some sites. Also inexpensive enough to swap & ship when needed