Take a long hard look at
why you want a Cobra. If it's because you want to own and drive one, then you're probably better off buying a complete car. It's easy to get frustrated and cut corners if your singular focus is on getting the car finished so you can tear up the track.
For me personally, it was because I wanted to build a car! At least half of my enjoyment of the car has come from the build. It was an incredible experience for me and I don't regret one minute of the 300-400 hours it took me. Of course owning and driving a Cobra replica is a nice fringe benefit too!
I've put over 11k miles on mine since last May and enjoyed every minute of that too. I drive it every chance I get, but I still dream about building another one!