DHCP options 66 and 67 are set for the scope correctly.
I have downloaded and tried both 4.0.0 and 4.0.0 (32 bit). I rename them from bzImage to 4_0_0 and 4_0_0_32 and am manually using that as the kernel in the host configuration. During the PXE process, it does read the correct kernel, followed by init.xz. However, still hanging on Using Hard Disk /dev/sda