Hello Lineslinger,
You thoughts on a project for the family with you and your children are great.....I grew up with a father and Uncles that built in me the fire to always have a project and the skills to execute.
As for your thoughts on a Cobra and then the high speed aspects that have been mentioned.....Pete Brock and Bob bondurant faced that issue in the 60's.
Voila...
http://www.factoryfive.com/table/ffr.../coupekit.html
The Daytona coupe....FFR's rendition expands the size a bit and gives you the formula Shelby started with and still endorses today...Small light package, Big Motor. This will not break the bank and will give you the project you were looking for. The Coupe is a more difficult build than the FFR roadster but, there is a support group of builders and the knowledge base is building up to where the FFR roadsters are.
http://www.ffcobra.com/ubb/ultimatebb.php?ubb=forum;f=5
This link will take you to the FFR Type 65 Coupe forum.
Enjoy the decision and the project,
Tony R.