Cipher suite priority
These are all fine and the order seems reasonable as well. It is a judgement call which part you think is most likely to fail. I would use your order of preference for the elliptic curve algorithms. GCM vs. CBC is a case of which you find more likely to be badly implemented.

If the requirements are not enforced upon you, I would consider adding in P-256. It should be as strong as 3072-bit RSA, and it at least used to be slightly more widely supported than P-384 – I have not seen recent numbers though.