Stolie,
The answer to that question is, the kit that's best for
you.
There's several question you need to answer for yourself.
How much mechanical skill do you have?
How much money can you spend?
How authentic do you want your Cobra to be?
What is the reputation of your prospective kit manufacturers?
Do they have a manual?
How is their support?
What kind of assembly stages do they come in?
On and on and on.
I suggest you get all the literature you can from all the mfg. you are interested in, an compare them against each other. Get the answers to the questions above and any others you may have.
LOOK at each mfg.s car, both finished and in raw fiberglass. look at their frames and all the other parts. Go to some big car shows were there's sure to be some Cobras. You'll be able to see several mnufacturers in one place.
Basically, prepare yourself in whatever way you can so that in the end you get exactly the car you want. You're going to spend a fair chunk of change on a Cobra Replica, you don't want to be disappointed by your decision in the end.
I chose a Midstates because when it was all said and done, it was the best car for me. But that doesn't mean it's the best car for you.
My $.02
P.S. Here are some, and this just my opinion, that are very good kits. There are no doubt some I missed, but this is a good start.
Midstates (of course)
ERA
Kirkham
Everett Morrison
A & C
Unique
Johnex
As I said, there are more. (So don't flame me if I missed some)
Dave