Slave is $200+ for our cars. I've read that you can easily modify an f-body one that is 1/2 the cost. They can be found just about anywhere that sells parts.
I've heard mixed thing about Spec and great things about Monster. I also think Spec offers flywheels also.
Unless your looking to do alot more power then are estimate, Why not save a crap ton of money and just go with LS7 clutch/flywheel route?
2003 Corvette Z06 - MGW shifter, Corsa X pipe, Corsa Xtreme exhaust, Texas Speed long tubes w/o cats, PowerStop rotors/pads, Conti DWS tires, C6Z51 F&R sways, C5R headlights, tuned
04 GTO - sold