This is 2 months old, but it looks like you didn't get a working response.
Mandy, WDS is an MS technology that allows PXE booting of a diskless WinPE2.0 environment. The WinPE environment has MS imaging tools that run thus resulting in a zero touch boot and install process. Altiris has a similar option.
I would imagine you will need to put the WDS server on the quarantine VLAN, not modify DHCP at all. WinPE does not support SEP/SNAC, so the diskless image will not pass HI checks. (I've spent hours trying to get it to work various ways, with no luck)
I would also follow the directions on how to include SEP/SNAC pre-installed in an image (have to get rid of a HardwareID reg key) so it registers properly after install and so the new client comes up on the correct VLAN at first boot after imaging.