Have you reviewed the existing topics on this subject? Use SEARCH.
The first question is what is your budget.
Don't build it your self. Find one that is already built or a roller and have someone put in the power train (engine/trans). Nothing is more sour than putting all the money into a car to build the perfect one only to find out it was a marriage made in hell. Buy a finished car that fits you (there are lots of them out there, but don't buy a car you haven't sit in) and then if you still want a Cobra but the first one isn't just right then spend the time and money to fine tune one for yourself. Start watching
www.cobracountry.com for cars in your area.
This is not a search with instant gratification. A build will take a year or more. A patient search of an already completed sorted out car could take as long.
Whatever you do don't buy someone's unfinished kit thinking you'll save your self a lot of money. Most are incomplete and the missing parts aren't available any more. If you're a fabricator with all the tools and knowledge go for it but most kits sit for decades for a reason.