It's worth noting that only pre-2013 Itanium CPUs are not vulnerable to meltdown (The same as with Atom CPUs). Intel has also said that the Itanium chips released in 2017 would be the last Itanium chips they will develop, so I don't think there's any reason to bother switching to Itanium. I would wager it's guaranteed you'll be better-off with the latest AMD instead of a 2013 Itanium, and AMD supports x86-64 so it doesn't require making your full software stack support Itanium (Which it likely doesn't).
I am sure you didn’t mean it this way, but it struck me as funny saying AMD supports x86-64. Of course AMD supports x86-64, they invented it. That is why Microsoft and Linux refer to that architecture as AMD64.
