you don't need the 60 option.
and for the boot file name put WDSnbp.com
if you put option 60 you need to provide option 43 too.
> Using DHCP Options 60, 66, and 67
> Although Microsoft does not recommend this method, you can use the following
> DHCP options to direct PXE clients to an appropriate NBP to download:
> Option 60 = client identifier (set to the string PXEClient)
> Option 66 = boot server host name
> Option 67 = boot file name
> End result:
> I can get an IP address from the DHCP/WDS server, but nothing more. It is as
> if WDS does not respond. What information do you need to help diagnose this?