Remember that different SKUs doesn't always get you the complete answer. My ATT iPhone 5s has a different SKU from its European counterpart, but I roam on LTE in many European countries. You may gave to be a little picky about the European carrier that you want to go with, but there is more overlap with each release.

I would keep my eye out on the Nexus 9. There isn't much on the LTE version yet.