City instead of suburb should be fine, as long as it ends up in approximately the correct order the postal service will likely figure it out.
It's a dumb idea to force people to use your local address format if you're aiming for an international audience. Just study the address formats used across the world and you'll quickly come to the conclusion that the only viable way is to provide address line 1 to n. Countries may put street numbers before or after the street, street numbers may not actually be just numbers, some addresses use building names instead of numbers, some countries require a state, province or territory, some countries require some sort of post office number in addition to city and postal code, some require locality, the list goes on. Just let people format their own addresses, then at least half of them should be able to get it right
. You'd be surprised how many people have trouble spelling their own name.