Which Lonesome Road ending would be most appropriate for an Enclave character?

Probably bombing none, seeing as the Enclave was about preservation of the human race and viewed anyone irradiated as non-human, and of course bombs would only contribute to the non-human population.

Also gotta consider that the Enclave population, AKA pure strain humans, are currently spread out all over. It's confirmed that Enclave citizens exist within the NCR itself and settlements on it's outskirts, not too farfetched that some might live in Arizona as well. Thus, there's high potential to hit other pure strains when launching the nukes.

To be fair the Enclave who were killed by NCR would most likely want NCR to burn for they did to them. Like hunting them down and etc..

Arizona they likely would not nuke. Mainly due to the fact the fact what Longknife said.