Dont go repro, the ZR1 OEMs I got were pretty damn cheap ($1395) and you cant really beat the performance for the price. Got them from Bob and HOW.
2014 ZL1 Speed Inc 799/751
2011 E92 DCT ZCP Stock
2009 Z06 Speed Inc Built
2008 E90 6spd ESS-Meisterschaft GT-AA Catless X-Volk TE37