You’ll need a Tech II full kit, incl.
1) the Tech II itself,
2) the standard Tech II main cable (“DLC”),
3) the CANdi module,
4) the standard SAE ODB2 adapter,
Pretty much every Tech II kit will come with all this stuff. Just make sure it has the CANdi module, and specify the GM software.
There are also a bunch of other adapters you won’t need for standalone operation with your Corvette. But those should be included, too.
Most people don’t opt for the carrying case because apparently it isn’t very good and it considerably increases the shipping cost.
*EDIT: there’s also the VCI module that goes inside the Tech II. It’s basically part of the Tech II itself and may not be listed separately.
*IMPORTANT: read it before you make a purchase!!!