Have you used butterfly handlebars before? They aren't everyone's cup of tea. You could have also built the bike around 700c wheels if you wanted, they are available at almost any Canadian Tire store in Canada but if you start with goodtires like a schwalbe marathon you can probably not have any real tire issues, or you could just bring a folding spare and change out your rear tire near the halfway point if you get flats. Honestly if you can return the surly frame and get a complete bike you'd probably be better off from a financial perspective even if you want to swap out the bars or something else.