William,
I haven’t used cobbler with ESXI in a while, so I don’t exactly remember what the parameters were... but I know that you need to have a couple of kernel options set in your profile. I had my setup completely automated, but it got erased when my section got reorganized. Ideally you should be able to press the power-button and have your OS installed, updated, and setup for you. Admittedly, what I mostly worked with was kvm or bare-metal, but I had some ESXI servers in the loop as well.
Let me see if I have any notes from left over from that project. In the meantime if anyone else knows the answer off the top of their head please let us know.
I am at work right now, so it might be ~7 hours or so before I can get back to you, but since we are likely in different time-zones, I'm sure that isn't a problem.