Which is best
 

Looking at purchasing x2 bikes in Canada and touring north and South America from early august for 12 months
I’m also waiting on a quote for two bikes air freight from nz to either USA or Canada start before deciding on which option
Any advice on those that have done this regarding tip v carnet etc
We may look to ship bikes to Uk after or head back home to nz
I understand I will need to show an exit flight either way on arrival
Thanks

Hi and welcome,
No carnet needed anywhere in the Americas north or south and the same in the UK and Europe.
Although shipping/flying your NZ bike can be expensive consider what would you do with a Canadian/US registered bike in Europe or South America at the end of your trip if you go down that route.
When arriving in North American a return ticket or one for onward travel can be helpful/essential, US immigration in particular like to see one preferably for a couple of weeks after arrival and buying a refundable return can be a good idea, I cannot board a flight to the US without one from the UK.
Search existing threads for advice about the places you can buy and register in your name in North America if you decide on that.