There are a couple alternatives. CCW has a nice wheel for about $1,750.00 and is about a 1lb lighter overall. I am currently working with Circle Racing Wheels. To build Factory Offsets & Widths, however be closer to 3lbs lighter per wheel! They should run about $2200.00 If you can get a 'True' Stock Z-06 wheel for $1,500.00 or Less that would be the best buy. The Chrome Replica's weigh a bit more, however you could purchase those for the street, and use your factory wheels for the track!
Take Care,