I have owned and built 4 Factory Five Cobras , I have been in a gtm when it was driven. Nice car , but visibility sucked !
I can also help you out with insurance , I paid $350 / a year for a Cobra that was insured for $35000 . There were a few stipulations , you need another everyday car ... simple stuff like that.
You can build a GTM for alot less than 50k if you can do all the work , and it is not that hard to do. This car would be easy t obuild compared to the Camaro you built.