best 221 head gasket

[xpcoupe221]

Im looking to buy a 221 head gasket for a turbo application. Im told this will be the weak link so I need to put the best gasket on there I can. Prefer not to oring the block but will if its the only way. Any ideas

 

[xctasy]

appco 630 composite. 45 thou thick. ACL or Repco sell it. Best 30 bucks I ever spent....