Replacing damaged screen and chassis questions

Hi everyone,

My Macbook Pro 16" Max (M4 2024) suffered bad damage in an accident and I need to replace the screen, top case, and bottom case, and I have some questions I can't find answered elsewhere.

Firstly, Apple Self Repair isn't available in my region, is there any other source for official replacement parts? And at what point in the cycle do sites like iFixit start offering parts for newer models?

Secondly, I've read about issues with 'parts pairing' but I'm not sure what the implications are for my situation. The Apple documentation indicates that after replacing a part I need to run the system config tool to pair the part. Am I right in thinking that this process will only work if I am using new 'official' Apple replacement parts (direct from Apple's Self Repair store)? And if so, does that mean parts from sites like iFixit have similar paring problems to used parts?

Any other suggestions toward resolving this also much appreciated.

Thanks.