I was back at the new client again today waiting for Comcast to deliver the SMC 8013. They didn't. In fact, the tech told me that they're incompatible with their network which is why they use the 8014.
Long story short, the tech installed a replacement SMC 8014, I turned off all of the services, plugged in the Airport that I had pre-configured with DNS, routable IP, subnet mask and gateway IP, and it worked. I was shocked, and relieved.
Now the client has wireless access, something they had never had before, and their freelancers can connect from home to work on projects.
Everyone is happy!
Erik