At my company we are doing something similiar. But now that HPE has http boot, we skip the dhcp, tftp, and pxe. In my case I piggy-backed off of rear backup. I created a rear backup of a EL7 install, then edited the ISO it creates to point it to a kickstart file sitting a web server. Using http boot, we point it to the iso, also sitting on the web server, it boots, loads the kickstart, and off to the races. I did have to do a funky work around to be able to connect to the host via dhcp. I ended up adding the serial number to DNS and having anisble connect to the host that way to finish the server setup.