I'm in the same boat as you actually. Although I can understand their need to differentiate between project car and second car. I know you say it makes no difference, but you came to ask for everyone's advice, and it does make a difference lol
I actually thought about trading in my 14 v6 before its worthless, for an older C5 vette and a AWD sedan for the winters. The LS motors are pretty proven, and I'd also have a winter beater which i dont have right now. Food for though, unless you're a Ford-only kinda guy.
The Cobras are obviously an awesome option, but good luck finding a decent one for under $15k.