Try www.clubcobra.com for a pretty active cobra board. From what I read, Super Performance builds a top notch performance replica. Lone Star offers a nice kit for the money. Factory Five is one of the simplest to build.
My wife says if I buy another Mustang, she's gonna divorce me. I'm sure gonna miss her....
Midstates in Nebraska, can be found under cobracountry.com
The cars are so well designed and fabricated they dont have a assembly manual!!! I have built approx 20 some turnkey cars for them. I also built 194 round tube original style frames for them in a 10 year period.