A full bolt-on C6Z with coilovers is showing its ass to almost anything on the track. And they're plenty of fun on the street, at least to me. That LS7 at WOT is hard to beat...
I'd get an '08+ as they received a newer/better trans, the TR6060, and a bigger dry sump tank, or even better, an '12+ as they had some upgrades from the ZR1 available(ie PTM and mag ride).
And if you don't like it, you can flip it pretty easily.
