how many more engines will it take before you realise that twin turbo setup is fundamentally flawed?

the fact it keeps blowing up indicates there is a problem with the setup/tune. trying to find rings that won't break is treating the symptom not the problem.

personally I wouldn't put a good bottom end under that setup until you have it sorted so that its not blowing engines up all the time. replace the one broken piston (or whatever the problem is this time) and have another go at sorting that setup and tune out properly. then build a good engine.