Shop local and talk to the guys at Yella Terra. They do some really nice billet steel flywheels. I bought mine throught them. They should be able to supply one to suit what ever clutch hat bolt pattern you have. Their quality is top notch and they ship them all over the world as OEM manufacturers for other brands
They can also do lightweight steel flywheel. I believe a stock LS1 flywheel is 10.5KG but my Yella Terra steel one is only 7KG. An aluminium one is 6.5KG.
Yella Terra
Windsor Flywheels
Cheers