doctorate in North America??Watch
PhDs in the US and Canada are very long like 4-5 years. But anyways at the PhD level its all about what you are interested in research wise, so really we can't help you.
Remember though that the US PhD program doesn't require a masters for entry, there will sometimes be one built-in (issuable on completion of coursework requirements) though many students won't even bother to pick it up.
No, if you're doing a PhD they are (almost always) paying you, and certainly at the kind of school to which a student graduating from Cambridge would apply.
For those who tried applying on both sides of the pond, where was it easier to secure a place for a PhD (assuming funding is a non-issue)? I don't want to waste money on application fees.
In terms of just getting a place (i.e. not funded) then the odds are much better in the UK, generally. It's relatively easy to get accepted in the UK if you have solid past results and a sensible proposal. It's then very hard to get funding. In the US it's very hard to get in, but most places only accept you if they can fund you (though this varies a bit among disciplines - and there are some more vocational disciplines in the US where it's fairly easy to get in too, and where the funding is correspondingly less assured).