jcooper,
First and foremost, welcome to Club Cobra ... you came to the right place!
I agree with what was said above, go through the manual and all of the options on the ERA web site. There are numerous build threads as well to read through here on CC. This should give you a good idea of where to start your project and figuring out what you and your son want to tackle, and what you want to have ERA provide / assemble.
I would recommend having the frame powder coated, the body bonded to the frame and having Connecticut Custom (an excellent ERA vendor) do the bodywork and paint. That should give you a good starting point, with lots assembly left as a great father / son project.
I don't know what the current lead time at ERA is at the moment, but you will have plenty of time to figure things out. Peter and the guys at ERA are great to work with and in the end you will have a beautiful Cobra.
Are you thinking a 427 Cobra or a 289 Cobra ... can't go wrong with either one ...
Keep us posted!
- Tim