In need of some help! I’m stuck for inspiration as our wedding is travel...

You could maybe name your tables after different places and have the centrepieces slightly different to suit the table name. You could make confetti from old maps for the tables and have a map table plan. You could have people sign a globe for your guest book. If you look online you can also purchase suitcase favour boxes for a reasonable price if you shop around and you could fill them with sweets from Home Bargains or somewhere.

I have painted bunting in all the flags of the countries we have been together

We are doing this too.
We are having table names named after places that we have been with favours incorporated to that place.
We are using a map of the world as the background to table plan.
Using a globe as a guestbook for people to sign
Were having a suitcase as our card postbox
Invitations were postcards

Pinterest is really good for ideas :)

Sorry (I can't help) but Chloe R your wedding ideas sound amazing. Really fantastic ideas to incorporate travelling!
My only suggestion, i've seen a cake idea of travelling

How about old suitcases from thrift shops? maps etc maybe pics of different places you have been on each table.

You can use old suitcases for card boxes, name tables after places you have been and you can have tickets as your invites :)