Lowering compression

To lower the engine's compression, new pistons or go to D3 heads.
Probably should go for new pistons, that way you will have a fresh cylinder bore and new rings.

You can't win. Some of the latter model heads have hardened seats at least. The C8's with big valves and hardened exhaust seats would be nice though. Either way or both, just depends what you have and what you want to do with it and spend.