Having been in the same situation I can tell you that there are many factors to consider before making the decision to go to the Caribbean as a Canadian.
It is infinitely more difficult to obtain a competitive residency without a greencard. The bottom line is that if you are an IMG and you also don't have US citizenship then you are in the position of taking one of two visas:
1. J1 -- you must return to canada for at least 2 years after you residency training or you must obtain a waiver (only offered in certain geographical areas). J1's are easier to obtain, but still some programs will clearly tell you that they don't sponsor ANY visas.
2. H1 -- this is what everyone wants. It allows you to remain in the US and transfer to a permanent resident after residency. But programs that sponsor H1's are few and far between. Specifically, very few of the more competitive residencies (radiology, anesthesia, EM, opthamology, even PM&R) will be willing to sponsor visas. Within the realm of IM, FP, Peds it is not too difficult to obtain an H1 as long as you are not picky about what part of the country you end up in. And here's the last thing about H1s, you can not even become eligible for one until you have written step 3. So if you are going to go to a caribbean school DO NOT start in the september class. The January start date matriculates 6 months later but it also gives you about 6 months before the start of residency application and you can get your step 3 written. Remember you can not even appy to write step 3 until you graduate from medical school. Accordingly if you matriculate from the september class you will be forced to take a year off before you can apply for an H1 visa.
I have seen a lot of Canadian peers who wanted to do competitive residencies face hardships even though they worked tremendously during medical school and achieved great grades and scores. Programs don't want to dip into the IMG pool as it is -- they certainly don't want to do it when the hassle of a visa is involved.
My advice is if there is anyway you can avoid going to the Caribbean as a Canadian, avoid it. If not make sure to think about your career in advance and plan accordingly. Take steps to make yourself a more appealing candidate in other respects. And of course make sure to start in the January class.
If you have any questions..feel free to PM me.
Good luck
